You can get a lot of good information and reviews at
www.projectorcentral.com which is a great site.
To elaborate, it really makes sense for you to describe the conditions you are looking to put a projector into.
1. What size is the room?
2. How much control over light will you have?
3. How far away from the screen do you plan on sitting?
4. Do you have a specific screen size in mind?
5. What do you plan to watch on the projector mostly?
6. How much money do you have to spend on JUST the projector?
Generally speaking, a person should have 100% light control in any room a projector is going into. I currently am installing multi-zone recessed lighting in my family room/theater. It works out so that I really can't use the projector during the day due to large windows, but now at night, I can turn on the rear lights while leaving the lights near the screen off. 100% dark is ideal for critical viewing and top notch performance.
Some people don't like to hear it, but if you can NOT control light, then perhaps front projection is not ideal for you.
The next consideration is seating distance/screen size. THX (heard of those guys?) have published standards which are worth following. But, generally speaking, the money seat will be center screen 1.5x the screen width away from a HD projector.
http://www.myhometheater.homestead.com/viewingdistancecalculator.html
Do NOT start looking at inexpensive business class projectors and thinking "Wow! What a deal!!!". Business class projectors are missing almost all the stuff that makes a home theater great including image processing, color, and calibrated contrast ratio. Typically business projectors are noisier, and will simply look horrible with television when compared to a home theater projector.
Projection calculators are references only, and when it comes to 'brightness' you almost never have a home theater projector that is too bright. This is entirely because the calculator is using manufacturer specifications which rarely is accurate for post-calibrated brightness. If a projector is too bright, you can set the projector on low-power mode, or even get filters that cut light output.
Most of all, ask a LOT of questions and do a lot of reading. You will find that there are many people with good info on several websites that will help you out.
