regarding the agreement form, it really depends what you are endeavourning to achieve, we offer a number of options ie monthly contract, three monthly or six monthly and offer discounts for duration of contract.
one clause that you need to include, in both the client and employee contract, is that of client not employing your labour directly for a period of time after termination on contract, and vice versa a restraint of trade from your employees approaching directly your clients.
if it were tested on court you may loose, however the clause in the contracts usually works.
regards
martin