If you've ever used WordPress before, you'll notice that 99.9% of the themes out there include hyperlinks in the footer of the theme, usually linking to WordPress and/or the theme creators' website.
So if you want TONS of quality backlinks quickly and easily, what I suggest you do is this:
First, find a popular theme that lots of people are using. Then simply approach the theme creator and ask how much they want to put your link in the footer code.
Now, any time someone uses this theme, your link will show up on the footer, and will likely get indexed by Google. Plus, these are site wide links, so if the blog ends up getting a decent Page Rank, you'll get LOTS of link juice.
I've actually bought these links for $200 or less on popular themes, and ended up with THOUSANDS of natural backlinks over time. If you're going after an ultra competitive keyword, I highly recommend this strategy.
You can also create targeted themes yourself (eg medical themes) and upload them to specific theme directories for more targeted backlinks. But either way works very well!