I'm just going to order a server from intensinfo.com and because I couldn't afford a dedicated server straight away I'm ordering what they call a dedicated server in a dedicated server (virtual dedicated server), it has root accses which is what I need but are there any limitations to these server that I should be aware of if I'm planning on hosting about 5sites on it?

I wouldn't say limitations is the exact word. Everything has limitations, an account on a shared server, a virtual private server, and a fully dedicated server. There are differences between a fully dedicated server and a virtual private server. While it acts as a dedicated server in many ways, certain resources such as the cpu and ram are shared and I suppose this could be a limitation but again, I see it more as a difference more than anything.

Actually we usually allocate a min. of 256mb of Ram per private server. Though only negative is the CPU sharing.

Joe