Almost all hosts oversell - that means you need not worry about the space and bandwidth any more.

That also means you will have to worry about the uptime. Go with hosts that has a good reputation of providing good uptime.

Customer support is also very important. Some hosts just give you a copy of TOS if you ask a newbie question. Go with a host that has a friendly support.

Your PHP configuration and features supported also matters. To make it simple, go with a host that offer "cPanel" control panel. You are sure to get almost everything you might need.