A few points I would include would be allowable usage and up-time (if you state a percentage or guarantee). One method you could use would be to read through popular hosting companys ToS and in a sense, rehash it.
Either way, you should consult a lawyer to make sure your TOS/AUP meet your needs, are legal, etc. It's a small price to pay for getting it done right.
More specifically what you allow to host, and refunds and other privacy polices. You may need lawyer help depending on type you rules.