“mom test” your project - put it in front of a non-computer literate person to see if it is intuitive.
Prioritize your features - develop just one or two features at a time, but polish them for your user by the end of your iteration.
consider a user research phase. Go out and figure out what your target audience needs. Learn what your users will want before you decide on the features of your system.
From a UX perspective, the users goals should not be framed in terms of a particular tech solution. You want to understand your users goals before you decide on a system that will solve them, or you'll get tunnel vision.
find a user who is similar in mindset to your end user, and test against that person.
It is ideal to have a end user (customer, or customer advocate) in the loop daily. If that's not possible, try to at least meet with that person on regular intervals.
To test against a working web prototype…
there are some tips coming from the book “don't make me think”
it's helpful to let the user be alone in a room using a computer with screencapture and a webcam - record their actions as they go through the test scenarios
on your test sheet, don't use the terminology from your website when describing the user tasks.
Steve Krug's “Don't Make Me Think” recommended as good book for understanding usability