Hi millipede, you can get waterproof writing pads or covered clipboards,a reasonable digital camera may help (some allow voice commentary and or short video clips), a voice activated tape/digital voice recorder is another option have a look in
www.alanaecology.com
Collecting insects is fine as long as you are responsible enough to put them back where they came from make a pooter and a small soft net to collect specimens a lidded box with a shoulder strap and a number of small plastic food boxes sold for about 40p in asda suitably ventilated of course