Looking at it as a pure user, it's not cr*p, but I don't rate it highly. As a prototype, it's a worthy effort.

Fault: on the front page, you have two sets of identical buttons pointing at the same page. Redundancy is not good. Further, the vertical set is on the right, not the left.

Possible solution: make UI consistent and eliminate redundancy. Investigate use of frames.

Fault: I went into the Products page and immediately spotted the 'Check the XXX in red'. Your titles are red. Lesser fault: you need to consider those users who, for whatever reason (colourblind / mono screen / blind and using a reader / whatever) cannot tell that something is red. BTW Red/Green colourblindness is common.

Possible solution: use a marker instead.

Fault: buttons are at bottom of secondary pages. This wouldn't be a problem if I didn't have to scroll down, but I do.

Possible solution: use frames (or a reasonable facsimile thereof) to have a consistent UI with major options across the top.