I'm just going to hit the basics.
You have a partial Doctype which means some browers will go into quirks mode even though you have a Doctype.
You have two <style> tags when only one is needed. I would however, place your CSS in a file with a .css extension and link to it externally.
Start to use more CSS for your layout and start getting rid of the tables.
I'm all for minimalistic designs, but right now your's kind of screams that more needs to be added. Just adding some well placed color would be great. One example is where your logo is at. Since you are using a table with a border, there is empty space between the image and border. Define that area as having a black background and it would fill in the empty space.
Speaking of colors, my take on finding a color scheme, aka Spufi's Guide to Brain Farting Color Schemes, is this. If you have an image/logo, take some of the colors in it, and use those for your color scheme. It gets no easier.
Sematic markup is using markup that best descibes the information contained within the tag itself. Your markup fails a lot in this area. One example...
<br /><big><b>Are you interested in archery?</big></b> <br />
What is that really? Think of a newspaper and isn't that a headline? It is, so use a header tag, ie <h3>. Now you would have...
<h3>Are you interested in archery?</h3>
Header tags default to having spacing around them(kills the needs for <br>), being a larger sized font(kills the need for <big>), and has a bold font weight(kills the need for <b>). If you want to control who big the text is, how much spacing there around it is, or anything else, do it via CSS.
About your menu, the Taming Lists link in my sig will cover that better than I can.
I would move your form for further info to the bottom of your menu.
I would think about putting the tournament links under a header named "Tournaments" and then display the dates under the header. I don't see the need to have the tournaments be in seperate <td>s, or the need for the Pig Roast link to be a different color than the other one. I would put the tournament dates within a ordered list tag since you would be putting them in chronological order.
So is that enough for now, or do you want me to check all of your pages? :p