Useful Links
My Little Wiki: G1 Accessory ID
The Wiki is a community knowledge base already huge in size and still constantly growing. I myself am an editor there, mostly working on the accessory and Nirvana sections.
My Little Wiki: Lady LovelyLocks section
I found accessory ID for this toyline especially difficult at that time, so I added that section to the MyLittleWiki. To be honest, I have yet to "complete" it, have many items not pictured yet.
Good to know: the MyLittleWiki also has sub-sections for Moondreamers, Glo Friends and Fairytail Birds!
My Little Pony Accessories
Chrissytree's website for accessory ID with wonderful, high quality photos. I find it particularly helpful as a resource and a great complement to the MyLittleWiki.
My Little Pony Stickers Gallery
An impressive collectors' resource for My Little Pony stickers, also by Chrissytree.
MLP Arena
Still seems to me like THE place for the community to meet. Be it for restoration advice, price checks, trading without Ebay fees or just submitting a new brag, this is the right place.
Ponylande.de - German Collectors' Resource
Sonnnnne's page - this site is fully in German language. I usually use it as an additional resource for accessory ID through MOC images and for German pony names, as for every pony released in Germany, the German name can be found there next to the English one. A separate names list is available, too.