First of all, make sure the design of your website speaks "Ease of use" to all visitors! It's your business card and if you make things complex, possible employers will look elsewhere.
Second of all, whenever you do something (write a blog entry, modify a page, do something else) then make sure the site shows a short time-table displaying when you modified it. With most blogs, this is automatic, but in other parts you might want to add timestamps. This is practical for employers because they will be able to see how often you're spending time on your own site.
Make sure you don't spend too much time on your own site! Employers will fear that you'd be working on your own site while you should do your job instead! If they notice that you're spending 3 hours every day online on your site, you'll stay out of a job for a very long time unless you can prove you're one of the few top programmers.
Add a robots.txt and make sure your site won't be crawled by Google. While it's great that people can find you on Google, you don't want to be a victim of identity theft where someone else pretends to be you when applying for some freelance job, just to take the money and run... To reduce the chance of identity theft, put a recent picture of yourself on your site, preferably the picture from your password.
Keep your texts short. No employers would want to read long stories. Actually, many members of SO probably won't read this answer because it's too long! Yeah, I know it's long. But when you've read to here then you've already seen several practical tips. :-)
Don't put too much personal information about yourself online. For example, publishing your home address plus information about where you're going to spend your Christmas Holiday might mean you'll have to buy a new inventory for your home when you return. It's not a big risk but it's bigger than no risk at all.
When publishing information about your girlfriend, parents, friends, relatives and other people, please make sure you notify them about this. It's just polite. Or keep them anonymous. Especially when you put pictures online, it's nice to warn people about this.
Make sure your site doesn't use copyrighted material from others. This even applies to small icons and simple code libraries. Check the license first to make sure you're allowed to use this material on your site. Preferably create your own content, though. Even though it might not look as good as the stuff from others.
And about your CV: make it available as a Word document, as a PDF document and have some pages that will allow visitors to just browse through it with an easy view. The documents should be short and plain. The site can be more complex as long as it's easy to navigate and doesn't display too much information. (Consider using collapsible panels to show/hide certain parts.)
Best theme to use is a generic design for your page. Look at SO for an example of this design: There's a header with generic functionality plus a footer with copyright information and contact information. Keep this on every page! (In ASP.NET you would add header and footer to a master page.)
The middle layer would be divided by a left and right panel and a main area where the left panel is used for navigation and the right one for additional information and perhaps small advertisements. These panels would fit nicely in a sub-master page in ASP.NET.
The center panel would be your page, which could contain anything you like.
If you use open-source/commercial blog software on your site then this blog is likely to be already shaped in this generic way. In this case, it's useful to put the blog on a subdomain of your site to make clear it's different from your main site. Or use a more complete CRM product and try to put your custom pages within the design of this product.
About graphical art and pictures... If possible, always create your own images. It shows creativity, even though you think your images suck. I've created plenty of images that I don't like, yet other people seem to disagree with me. So I'm no expert on the quality of my own work. :-)
When linking to other sites, it is polite to just ask permission first or look if the site implicitly grants permission to link to them. In some countries, people have been sued for adding links to other sites and the outcome of such a case in court is still unpredictable.
Last of all: make sure every page displays a FAQ, a copyright notice and license information. If possible, add a thank-you list referring to other people/companies to thank them for their contribution to your site. (Just to be polite.)