Cable Chick's blogs contain useful guides, and tech info on all your favourite AV and computer cables, plus a useful guide for identifying what cable or adapter you need.
If you're trying to identify what kind of cable, connector or adapter required for your device, our Ultimate Guide to Cables & Connectors is essential reading. We've laid out a visual reference for most video, audio and computer plugs + sockets, so you can visually identify the plug/socket you have, to work out the cable/adapter you need!