I would first recommend to first start off reselling VPS servers. You can do this either by purchasing a dedicated server and setting it up to offer VPS accounts or join a reseller program such as jaguarpc.com offers.
I will recommend that you take a look around first, about what the Dedicated server Companies have to offer, compare their products and go with the one that you are feel confident or they can support you. One thing that you can do is to ask technical questions through their phone or chat and even emails and you will see from there if they know about what they are talking about.
I guess during the process of your comparison, you should have criterias, VPS is in a "shared" environment don't forget and you don't know how it is managed behind with the Hosting Co.
At least it is easier to go with a dedicated server, because it is not shared and you have the control of what your supplier can give you.