I use a fishing log book. Go to: http://www.sportlogbooks.com/fishing.htm if you are interested.

I keep a log.... weather, temp, water conditions, lures tried and failed, lures tried and worked.. along with pics of any fish... plus a small map drawing of the lake and where I caught fish.

I started keeping detailed records in 1972, at first they were hand wrote but now everything is in Micro Soft Word and Excel.

Date, time, & moon phase

Areas of the lake fished, types of structure, & types of cover

Water temperature & clarity

Complete weather report for each day

Lures, techniques, & patterns

Total number of bass caught

Total number of bass under/over 14 (Toledo Bend)

Weight of any bass over 4 lbs

I plan on keeping a journal this year. I printed off the pages last year but never filled any out. I don't have a GPS on my 12' boat but I do photocopy the lake map and approximate where I caught fish. These pages will then get stapled to the back of the journal page.