I've seen a few mentioned, i know there are apparently a lot of them and torhead has been fairely useless and now it's apparently DOWN...and has been all day for me at least (haven't tried a dns flush)
I think we should start a list of them here
So doyou have a swtor database you like using? is it deliable? Post it here!
www.r2-db.com (was originally going to be a db site, not sure what has really become of it)
There is currently no site that has all the information, since much data is still lacking and there is no solid mpq file like wow has for sites to data-mine. Until BioWare creates an api that allows for mods with hooks to actual items in the data we have, sites will have to rely on fan updates with hard evidence.
If you feel like all of these sites are lacking information you need (like myself some days), try starting forum posts on their sites asking for information or clarification. When you get the chance, also take the time to reply to some of these people as well looking for information that you might have and let them know about it.
There are a few threads on the official forums which you can consider fan updated information, while some of these have been made a sticky, BioWare/ToR mods/devs have yet to comment on any information to even try to help out the community in their understanding while the game in in its infancy. To their credit though, for a company to do that on every single question posed by their subscribers/fan base is near impossible. However we as fans, players, or subscribers, must remember that we may view the questions we pose and extremely important, they may not be to others and demanding responses from mods/devs (in my opinion) should warrant no response at all unless the thread got way out of hand.
As for hard evidence to support your claim to clarification about in-game items or mechanics, use screen shots and mouse overs (to view item stats and what not) so they can be seen. Using time stamps is also a good idea for your chat log so you can show the time between actions if submitting multiple screen shots.
Also, you can increase your chances for people to respond to your question by posting on swtor.com's forums, here, or on your favorite fan site and posting the same question here with a link to your original question, so people might have more chances to reply to it and see if someone replied to your original post if they are wondering the same thing.
If you feel like the information was verifiable or legitimate, try to replicate it for yourself, and submit to the db sites so we can help build these up as fast as possible with a wealth of information that players like us do like to reference.