VRG is fairly credible, they have been pretty helpful in the past. I have one of their books, it's an FAQ book of commonly asked Vegetarian/Vegan questions, it has everything from "Are tattoos/tattoo ink vegan?" to "What are hidden animal ingredients to take notice of?".
They have a lot of great research available, too, some of it is very useful (I like when they list sources, I like to weed through them and determine if they are credible, and it helps me find new reading material... this is how I found some of my favorite authors).
Obviously they have a bias (they are pro-vegetarian) but their arguments are fair and they do concede to the opposing viewpoint in some areas... for instance, the vitamin B-12 debate.
I like the VRG, I think overall it paints a pretty positive light on vegetarians and vegans and what being one entails. They're not a threatening group. I would rely on information they provide unless given reason not to (and most of their information IS reliable).
By the way... What is going on with this forum lately? :(