Ok... a few critiques. They may be nitpicky, but when you are using a site to make money, everything counts.
Red is not a pleasing color. I would recommend choosing a more soothing color scheme, like blue, or even allow the user to choose from a few themes.
Your ad at the top is annoying. Use Flash to make it more "flashy," or just use a static image. All you are really saying there is that users should register, and they can sell guitars for free. It is an image, so you don't need to say "click here." And, once a user registers, that ad needs to go away.
The image at the bottom is not clickable. It should be.
For print, a serifed font is perfect. For the web, you should use a more "pleasing" font that is sans-serifed. Stick to one font, and only a few variations. You can set the font in your body tag. I like Tahoma myself, but typical pages will use "verdana,arial,sans-serif"
I know that's a Website Navigation menu. You don't need to label it as such.
Use CSS to make your menu look more like menu links, and use padding and margins to make the layout "fit" better.
You have a login form, and a "register" link at the bottom of it. You don't need LOGIN and REGISTER menu items. Once a user registers, that form should go away, and say "welcome, [username]"
When I register, it says to use 6-16 characters. I used "BuzzLY" and it told me I needed more than 6 characters. NOT good.
I don't recommend you limit a person's password length. Some like to use long passwords, more than 10 characters. You are simply storing them (encrypted, right?) in a database, so why does it matter how long they are? For that matter, why does it matter how long the username is, if it's unique?
Links that change boldness can cause problems with layout sometimes. Instead, think about just changing the color of the link when you roll over them.
I personally don't like underlined links. So, I turn them off in my browser. When I come across a site that underlines the links ANYWAY, I find it annoying. I recommend not forcing the underline, and just make links a different color so they are recognizable as links.
Learn web standards. Using tables for your layout is not a good thing. Learn how to use CSS. For a great demonstration of what CSS can do for you, visit the CSS Zen Garden.
Remove the borders on your images. Most people know images are links, and they will definitely know when they move their cursor over it with their mouse. You are going for a certain color scheme on your site, and the blue border around image links just breaks up the scheme.
The image in your head should link me back to the home page.
That's about it... I know it's a long list, but I was very nitpicky. If you are going to advertise the site in a rag, and you want lots of repeat business, then even the smallest things make a big difference. Most are not hard to implement, and can make all the difference in the world between looking like "Yet another guitar-selling site" and "the top site for selling guitars."
I'd start with the most visual things first, like the font and your links. Then go from there.
Or tell me to jump off a bridge, and don't change a thing. Your choice 😃
Good Luck!
