MySpace offers a host of stock layouts and there are websites and designers that specifically design layouts for MySpace. A good idea would be for you to check out the stock layouts that MySpace has to offer and determine if they fit your needs. If not, do a web search for "MySpace layouts" and you'll come up with a bunch of results that will lead you to quality sources of both free and for-fee layouts.
Marketing affiliate products/services is just like marketing products/services that you might have created on your own. The best way for people in your target market to take you seriously is for your marketing to be compelling, informative and genuine. Blogs are good for achieving these goals.
If you blog, you can answer common questions about the underlying problem that your target market experiences without your product/service. Let's say, you're an affiliate for corrective shoe inserts. You can write blog posts about what causes foot pain, homeopathic remedies for foot pain, foot massage, the hallmarks of quality foot corrective products, etc. The topics could be endless. It's best to sit down with a pad and pen and write your ideas for blog posts down, this way, when you start blogging, you're never at a loss for topics. Inviting your readers to ask you questions it also a good way to come up with great content for your blog.
Also, if you think about it as if you were writing a book...what would your chapters be? Then break those chapters down into pages and you've got the makings of a good blog post. Keeping in mind that the average blog posts are 250-300 words - so there really is no need to literally write a book, when writing your blog posts.
Last, don't hesitate to ask the creator of your affiliate product for help in marketing. Smart business people know that nurturing their affiliates is good for business. Even if they don't have a formal training set-up, you'd be surprised. After all, you can't G-E-T unless you A-S-K.