If you are just starting out and plan in using the 15 gallon then go with a very small canister or a regular HOB filter, no skimmer needed. IMO get the cheapest lighting you can, even PC's would give you plenty of light penetration in a 15g. Salt is a matter of choice, you can't really go wrong. 2 clown fishg would be ok, and one goby. Throw in some top snails (
http://www.liveaquaria.com/product/p...55&pcatid=1755) , a few hermits and you're good to go. Def use sand over crushed coral.
There's a good starter package for a 15g.
Did that help?
O and stay away from starfish and the like until your tank is mature (6-8 months or so). The claim is they like mature tanks and stable water conditions. I didn't add mine till my tank was older so I can't speak to rather it is a wives tale or fact.