Having selected your target water, then some reasonable planning and preparation work is called for. The first thing I do is to draw up an A4 size map of the water. If you have a scanner you can scan the permit book map and enlarge/print it to suit. I divide the water into a number of named sections. This might break a 25 acre pit into 5, five acre chunks. You might consider splitting it up by compass points, eg: West bank, East bank etc.
To keep things legible, I use a clear acetate sheet (or OHP slide) to overlay the master map.
Having completed your initial intelligence that helped you select the venue, you now need to gather as much useful information whilst visiting the water. Fellow tench anglers are usually a friendly bunch and will be happy to chat if approached in the right way. In The Tenchfishers we have a free exchange of information among members so a subscription is a good starting point, it's odds on we have fished the venue you have selected! The Tenchfishers web forum 'Tenchtalk.net' will undoubtedly be a good starting point. Carp anglers are also a good source of information and do not view tenchmen as competitors! So wear your Tenchfishers T shirt and badge! Record all your data on your map set.