Looking after my banjo ?

I've only been playing about 2 months and never really thought I had to do anything to look after my banjo other than don't drop it and keep it in tune. Now I'm learning I should be giving it a bit more TLC , but do t really know how. Do I need to clean the strings, if so what with ?
What and how I clean the wood and metal ?
Do I need to take the strings off to clean the fret board ?