There are many forums on the web that can help you with your 3D questions. This is a short list of those that I have used in the past, or that I happen to know are very helpful. If you know of others that you would like to recommend, please write to me (chat at robinwood.com) and tell me about them!
Click on the names below to open the home page for that forum.
CG Society - High end, very professional site. They have a lot of Maya stuff; but also plenty of other application specific forums for both 2D and 3D creation and compositing. (Including Blender!) Forums, Wiki, workshops, job listings; and a gallery that will knock your socks off.
Luxology Forums - modo specific, on the Luxology website. These are very good, and the people are very friendly.
Renderosity - Forums specific to most 3D programs (click the Forums button on the home page to see the list. Also has stuff to buy, (use the Department menu to choose your program,) and Free Stuff if you're registered and logged in.