[jaguar]

Well, you asked for it.

Less animated gifs, it's like a small angry animal raping my eyes.
Header the sidebars, put the text about each item below it, easier to read, easier on the yes and easier to update.
A link up the top to the stocklist would be handy. Simplify and unify the colour scheme.
Move to a CSS based layout, renders better and gives you more control.

That's a starter list anyway. I know you're not a pro but I feel it's better to be honest than not. As I said, if you want help with any of this I can point you in the right direction and help fix problems as I'm sure plenty of other people here can as well.

You might want to consider moving to a package like Postnuke, it'll take the hard work out of it and give you more control. OSCommerce might also be of interest.