pretty much any shrimp will do.. from what i know ghost shrimp are very cheap ( 99 cents ) and very easy to care for,cherry shrimp are a bit more expensive ( $2.50 ) but are alot nicer looking than a clear see through ghost shrimp
as far as i know you can just drop them in the tank,make sure they are getting enough to eat and thats bout it. shrimp pellets may be a good idea.. youll probably want at least 10 shrimp