Make sure your bucket is water tight before using it for real.
If you are starting from seeds, then get some 1"or 2" rock-wool cubes and start your seeds in that. Keep it moist. When roots can be seen, put the cube into your mesh basket and pack it in clay pebbles. Nutrient level should touch the bottom of the mesh basket. When roots pop out of the mesh basket, drop it about 1" below for the rest of the grow.
Not alot you can do about water temps unless you have a chiller. Cool 70* water is best, but most just go with what ever happens.
General Hydroponics is very popular. A simple and effective feeding method is the
Lucas Formula.
Don't do anything without a good PH meter. Please spend more then $20 on one. It will be worth it to have a real good one or even two. It is possible to grow hydro without a TDS/EC meter, but extremely difficult if not next to impossible with no PH meter. PH will change alot, and if gone unchecked it can turn to acid real quick.