This is not an exhaustive list, not yet. I've started with the main conventions and will add my favourites and any others that appear popular.

In terms of external sites I recommend for its simplicity the Bridge Buff website.
I have also found no site more extenive than Bridge Guys .

Be warned that these sites and many others disagree over all sorts of things, and many are written assuming you play SAYC. But in any confusion I am always right.

Baby Blackwood Benji Acol Blackwood Cappelletti Checkback Stayman DEPO DOPI Fit Jumps Fourth Suit Forcing Gambling 3NT Gerber Helvic Inverted Minors Jacoby 2NT Lebensohl Long suit trials

Michaels Cue Bids Multi 2D Multi Landy Ogust Puppet Stayman Roman Keycard Blackwood Smolen Stayman Strong 2C Texas transfers Transfers Unusual 2NT