I have a variety of 3P guides tossed willy-nilly into my Pastebin, but here's a list of them:
1) Itemizer and Gearcollector (Highly recommended plugins)
2) LightLuggage (Also recommended)
** More extensive LightLuggage guide (by Yugl)
3) Guide to using Dropbox to synchronize your Plugins/Logs/Spellcasts across computers if you play on multiple machines
4) Guide for POLUtils re-naming
5) Spellcast Guide (by Yugl)
If you have any requests or guides of your own, feel free to toss them out there! I some day intend to migrate these guides to bgwiki now that we have permission to put some 3P stuff on there.