After wet rides on the nice bike I tend to blast the drive chain with the air compressor and relube, although not everyone has this facility. I personally wouldn't recommend using WD40 or GT85 as a chain lubricant, although it's better than no lubricant (unless it's a new chain, in which case it can wash out the factory lubricant).
I recommend the Finish Line range of cycle specific lubricants. After a wet ride, wipe down your chain with some old rags, then apply a drop of lubricant to each roller. Spin the pedals around for 30 seconds or so to work in the lubricant, then wipe off the excess. Remember it's the inside of the chain you want lubricated, not so much the outside.
When riding in the wet, you will find that dirt build up over the bike is far accelerated compared to on dry roads. Try to keep on top of this, and give your bike a quick clean when you get home - Otherwise your bike and its parts will end up filthy, which may reduce shifting performance (and looks!).
Don't worry about asking questions you think may be obvious to others - Everyone has been there!