I worked in this field for 35 years. It has changed a lot over that time, and much more can be done now than in the past. Digital video and computer based editing make things easier than it used to be, but QUALITY video production is not easy or cheap.
Here is a good site with some good info for streaming video.
http://www.streamingmedia.com/article.asp?id=9420
If you are simply going to be streaming video, it is much simpler than shooting video for broadcast, and people on the internet will generally accept poorer quality product, but that is not what you should try to provide. If you plan to provide decent video content, then you will need decent quality equipment. Lighting is one of the most important aspects of quality, but you will need mixers, codecs, editing software, synch generators (if you are planning to switch between camera on the fly), and much, much more.
If you want fairly simple video production capability, do a google for wedding videography production suites, etc. Wedding videographers typically use production equipment that is on the lower side of the spectrum. It usually provides pretty good product without breaking the bank.
Basically:
Buy a camera that has professional outputs. This way, all of your peripherals, such as microphones, will be compatible when you upgrade later. You will only have to buy the equipment once and it will save you money over time.
Get a good, basic light kit. Lighting is paramount when it comes to shooting good video and you cannot always control outdoor or indoor light conditions. Having lights you can add will improve the quality of your videos whether you're an amateur videographer or have been in the field for years.
Buy the best tripod you can get for the least amount of money. Tripods with fluid heads have lubricating fluid in their mounts, allowing much smoother camera movement than with non-fluid heads. If you go with a non-fluid head, chances are you will want to replace it as soon as you can afford better.
Upgrade your computer. To edit digital videos on your computer, you need to have enough storage space to hold large files and enough memory so the computer can handle the tasks you are asking it to do. Without it, the software can slow down your computer and increase the time it takes you to edit.
Choose your method of video capture. Firewire cards and cables are used to transfer video from digital camcorders to computers. If you have an analog camera, you'll need a converter device to convert the analog tape footage into a digital file so you can work with it on your computer and store it for the future.
Get editing software such as Adobe Premiere Pro, the standard professional software used for video editing. It has every special effect and feature you could ever want, but chances are you won't use them all. A lower-end package will save you money and have practical features you'll need to create professional videos.