10g not a lot to work with, so are you wanting only fish, fish and live rock(FOWLR), or reef? The easiest (and cheapest) would be fish only or FOWLR. For fish or FOWLR, you could just get a cheap stock light. For 10 gal you could do a couple of nano fish, some small shrimp-like sexy shrimp, and a few snails. You'll need a heater, salt, hydrometer or Refractometer, filter, liquid master test kit, RO or rodi water, powerhead to get started on cycling. Obviously you'll need food and some other stuff later. You'll have to monitor your specific gravity closely in a 10g cuz with evaporation, it'll rise quickly.
