However you've come to be here, you may be looking for just the nuts & bolts of the How To... if so, that's mostly in Part 2. What follows here is the initial thought process and decisions about what changes to make.
While in the process of updating my personal web site, I decided it might be good to have a generally matching theme for my blogs. (Or at least some colors and text that would look more the way I'd want.) For various reasons, I've chosen to use TypePad via hosting, rather than install MovableType on my own server. TypePad offers a bunch of easy to use themes and customizations, but if you want to have things exactly you're way, you have to get into the style sheets. So any customization I'd do would be via Custom Templates and editing the CSS for the Blogs. Either way, there'd be some decisions to make. And there's multiple ways to go about doing the design.
The first decisions are design:
Should the theme exactly match my web site?
That is, should I try to pull in the same surrounding masthead and navigation elements from the core site or allow the TypePad blogs to have their own design?
My Choice: The blogs will have their own simple design with an easy link back to the core web site. Reaonsing: 1) The complexity of my site's design and time/effort vs. benefit to create a match just for the personal spew in my blogs. 2) Burying the blogs under a bunch of surrounding design elements would likely impact Search Engine Optimization, (SEO), for the content. 3) Visually, adding the blog navigation components within the site design, (likely in a right column), would make for a slim center content column. 4) The user experience would likely be best to leave a clean and simple, "blog-like" design that focused on the content. 5) Most visitors, (assuming I get any at all), would likely show up directly via search or links. They proobably couldn't care less about my personal site or anything on it. They're there for the the core of the content and that's it. 6) If I'm not happy with the result, it's all CSS. It can be changed easily enough.
So what should the design look like?
Since I'm going to diverge from the 'mother site' I can do anything I want. What should I do?
My Choice: A simple, attractive theme that would have a similar color scheme to the main site, but would in the end be optimized for readablity of the content itself. To me, this means a reasonable width to the main text column and a decent font size. And I wanted to use a liquid layout whereas my main site is set up with absolute pixel values. Anyway, there's a variety of studies regarding text readability in terms of line lengths, fonts, etc. They're a bit inconclusive, but somewhat directional. (Usabilty News 7.2 Study, Reading Text Online, Font/Text Size.) Such studies focused on visual issues. Of course, there's more to online text in terms of cogntive issues and so on. (Improving usabilty for screen readers, a second reference to similar article, (to account for linkrot on one of them.)
I also know I'm not going to have time to do everything I want, like maybe use backround images behind some elements and such, so I want to set things up so I can easily get back to it at some later date. (Yeah, right. Still... I'd like to think I'll get around to it.)
Go to Part 2 for the details on how to make the changes.
Customizing CSS for a Hosted TypePad Blog: Part 2