Isomer Design
Cheminformatics, Access to information, Independent research, Peer-to-peer pharmacovigilance
isomerdesign.com
The Pihkal/Tihkal section is not only the books & chemistry but also contains 'explore' that allows 'novel' compounds to be drawn and if they have previously bee references, you can discover where.
Blotter has a growing set of NMR data so even if you aren't an expert, you can at least compare what you ordered with what was delivered/
Those are the three most powerful elements of the site but it's all of interest.
Sorry if it's been pointed out before, but it really is very good.
