Are you looking to reseller dedicated servers or shared hosting? To resell dedicated servers your best bet would be to contact a dedicated server provider and see what type of deal they can work out with you or maybe even post in the requests forums as I am sure there are some people here who can help you.
If you are looking to resell shared hosting then I suggest just taking a look around and find a few hosts than interest you and then to a search to see if any feedback is available for them.. You can also post in the requests forum but be sure and still do some searching for some info and check out the basics such as how long they have been in business, typical response time for support during different hours and make sure there is an easy upgrade path for the future in the event you need to more to a larger plan are a few of the basic things you should check into.