Some rooms will expect to get paid in some way, but in my experience it is far more common for the room to be willing to pitch in to have an event that will bring in customers that they would not have otherwise had. For the few that want to be paid, it is usually in the form of a green fee (part of the entry fees, say $3 from every $13 entry fee). The ones willing to pitch in do it in a number of ways. Sometimes they add money to the prize fund. An example might be $50 added for over 10 players, and $100 added with over 18 players. Sometimes they will pay the tournament director in cash or with a bar tab, although it is typically pretty minimal, usually $20-$30. There are other creative things that can be done as well (I have seen hourly or all-tournament drink specials for the tournament players for example). Some rooms aren’t going to do either one--they won’t expect anything from you, nor are they going to pitch in. And a few are going to do both, where they may want a green fee, and they will also add money to the pot or help in some other way (which has never made much sense to me but I digress).
IMO the way you should approach the room is with the expectation that they are probably going to be thrilled to have the opportunity to get customer’s they wouldn’t have otherwise had and will be willing to pitch in in some way, or will at least want nothing from you. Almost no chance I would consider it if they want to be paid in some way but this is pretty unlikely IMO (they need you, and benefit, a whole lot more that you need them, and there are too many other rooms that would be glad to have you and would want nothing in return or would even pitch in to have the opportunity). What exactly you ask for is up to you, and you can also make it conditional if you choose such as “if I can show you that we can average at least twelve players a week, would you be willing to kick in a $15 bar tab for me and add $50 to the pot?” You should probably also see what they provide, or ask for, in regards to the other tournaments that happen in the room so you have a feel for what you might expect before you approach them.
Scotch doubles tournaments come with lots of problems and I have never seen one work well for very long. You have to decide if you want teammates to alternate every shot, or alternate each inning (each shot is most typical and arguably most fun, as well as most frustrating lol). You also have to decide if they have to keep the same rotation when going from one game to the next, or if they get to decide who goes first in each new game. I kind of like keeping the rotation throughout the match so that it mixes it up where the same person isn’t always breaking, or isn’t always the one taking that first tough shot after the other team breaks dry or plays safe, and it keeps the stronger teammate from being able to carry the team as much, but either way is a preference depending on what you want to accomplish.
You have to decide if you are going to allow teammates to confer about shot selection while it is their turn to shoot. If you don’t allow it, it takes a lot of the fun out of it and you may not have as much interest from people. If you do allow it, be prepared that it is going to make some matches go LONG. Teammates will confer surprisingly often, and for surprisingly looooong amounts of time. You almost have to have some kind of shot clock rule that can be imposed at least when/if needed if you are going to allow teammates to confer during their turns. My preference is to allow it because it makes it more fun for everyone, but have time limit rules of some kind in place and known to everyone in advance because rest assured they are going to be needed at times. If you want to limit how long teammates can confer before shooting to say like one minute, which will probably be necessary, it comes with its own problems because who would be in charge of the time clock for it? It usually ends up having to be kind of an honor system, and if one team is continually violating their one minute (or whatever it is) time limit for conferring the other team’s recourse will be to get you involved to make some kind of decision which is never going to ideal.
As already discussed in the thread, you have to decide if you want to allow people to pick their own partners, or if you want to assign partners by blind draw, or if you want to assign partners based on something else like trying to keep the teams as evenly skilled as possible. None of these is going to make everyone happy. As someone else said, I think I would allow people to pick their own partners if it makes a team of reasonable strength, and don’t allow two superstars to pair together. Pair up the rest of the people who don’t have a partner in ways that make the teams as even as possible. You might want to use FargoRate to improve the accuracy of the pairings as well as making it objective instead of subjective so people will have less basis for complaining (although being that they are pool players you are still going to get complaints on anything you do regarding anything and everything so be prepared for it because pool players are never happy lol).
I have never seen or heard of it being done, but if the matches are long enough (at least races to 5 I would think), you might consider allowing singles to play as a one man team if they spot the opposing team a game on the wire (because having to play with a partner is somewhat of a handicap and this helps to even it up). This might also be a good way to handle when you have an odd amount of players and no teammate for that last person who ordinarily wouldn’t get to play. Any time you have an odd amount of people, ask all the singles who don’t already have a partner if any of them want to volunteer to be the one man team that has to give the game on the wire. If none of the players who aren’t yet teamed up volunteers, do a blind draw to determine which one will be playing as the one man team giving up the game spot. Or just do the blind draw for who will have to be the one man team without even giving the option for anyone to volunteer, whichever you prefer. Like I said I have never heard of it being done and don't know for sure how it would need to be tweaked to work well (or even if it could work well at all) but I think it might have enough promise to be worth experimenting with.
You don’t want these to be two hour tournaments because then it doesn’t help the room much, but on the other hand you don’t want it to go too long either because people only want to give up so much of their weekend time. I think planning for it to end by 5pm at the latest would be a good idea so people have time to at least get home in time for dinner and/or on to their other evening plans.
If you want to attract the top players, have higher entry fees and make the payouts top heavy, but you will get fewer players. Sometimes paying out too deep can cut down on the amount of players you get too. The best compromise to maximize participation is usually a low or moderate entry, and paying out about a quarter of the field with the money spread out pretty evenly. Often the lowest team in the money would have a prize just equivalent to getting their money back, especially when you get to pay a lot of places because you had a large field, and/or especially if you were paying closer to a third of the field instead of a quarter.
As has already been suggested, using BCAPL rules is probably be best. They are the most comprehensive, the most sensible, most people already know them (and they are easily teachable for those who don’t), they will reduce arguments, they are arguably the most fun, and they can easily be referred to in writing online when needed (or in a book for those that have them). However, if nobody in your area uses them and some other rule set like APA is what everybody uses, you may not have much choice but to use the popular local rules but I would try to use BCAPL rules if possible because they really are better.