Most web hosts that you will have heard of, are big
enough that you don't have to worry about their
servers, disk space, etc.
Support is the one biggest thing to consider in a web host.
How do you contact support?
Email ... web form ... phone ... online chat ... ?
Do they have good online help pages?
(Saves time and hassle for you and for them!)
How fast do they answer? Do they get back to you right away
if they say they will?
How well do they answer?
Do they confuse you? do they make you feel stupid?
Are they even rude? Then forget them!
You are the customer, you are paying them. They are there to serve you and help you.
How quickly and well is your problem solved?
Rule of thumb:
How much is your time worth?
If support is no good, then the host is no good,
no matter how cheap it is.