I am a much better designer than coder or content writer but here is my 2 cents.
Coding Review
First of all I will go ahead and say it, because if I don’t I’m sure someone will; tables are out and divs are in. I would not tell you to go back and re-write your whole site but depending how serious you are about it and how much time you are willing to put into it I would consider it. I was also looking at your search form on your home page because it is off centered, and I noticed some mistakes in your coding you might want to look at, like as you see below you have <strong> tags around a comment, which you really don’t even need; then it’s repeated several times.
HTML Code:
</tr>
</table>
<strong>< <!-- Begin Personal Site Search Form --></strong> <!-- End Personal Site Search Form -->
><strong>< <!-- Begin Personal Site Search Form --></strong>
<form method="get" action="/.search"><input type="hidden" name="results_page" value="my_results.html" />
<input type="text" name="query" value="" size="18" />
<input type="submit" name="name" value="Search" /></form>
<!-- End Personal Site Search Form -->><br /></td>
</tr>
</table>
This is all I had time to show you, you might want to give it a look through to see if there are any other things like this that could easily fixed. Now back to the search form, try this code below and see how it looks if you don’t care for it you might need to use margins. (Note – I know this might not be the best way to fix it but just trying to help you out, and I am limited to what I can see and do by just reviewing it.)
Just replace the above code in your site with the new one below if you would like to see how it looks, you might need to make some minor changes.
HTML Code:
</tr><tr>
<td width="215"><br><br><div align="center"><strong>SEARCH OUR SITE</strong><form method="get" action="/.search"><input type="hidden" name="results_page" value="my_results.html" />
<input type="text" name="query" value="" size="16" />
<input type="submit" name="name" value="Search" /></div></td>
</tr>
</table>
</tr>
</table>
Design Review
First thing, the header, I am not crazy about it. A few suggestions you might want to think about. (And this is actually a little more in my field.) I would get rid of the drop shadow and separate box. It’s like you have a header inside a header. Then I would get rid of the starry background, I like stars and in some places they can look really nice, but I think it’s a little distracting in this case. Maybe do this; have the world and blend it into the background green or fade it; and that will bring out your plane more. I actually like how you did Aviation in your header but then earth is different to me it does not look like it goes together; maybe do earth the same way.
I think someone had mentioned about needing another color in your scheme, which I agree with. Maybe a cool grey.
You had asked about suggestions for added content to your home site; so here are a few. Maybe some icons that showed different types of planes that you could click on that took you to a page that showed their specs. You could put an event feed of upcoming air shows or something of that nature. Maybe a section that showed new stuff that has been added like media, clips, or stuff like that. Remember that most sites have little writing on their home site, it’s usually a page with a lot of different icons, pictures, and pages to go to.
I didn’t mean to go this long, sorry I get carried away sometimes.
I hope this helps anyways. Good luck!
Try something new.
But it's just an example 
