For most people, you don't really think about coming up with a thousand dollars to market a single blog or site. I don't blame you either, it's not something you should have to do if you're making a blog for pleasure and just want the income on the side. We've all heard about the Google and Alexa ranking systems, but it gets to a point where all the sites that have the "best" abuse it and cause them to lose their top score. My recommendation to you is to not buy links at all and instead do your best to spread the word using forum signatures, social bookmarking/networking sites, and word of mouth. The fact is that the guys who win in the end are the sites that all the kids are talking about. Sites like PerezHilton.com, SuicideGirls, YTMND, and Last.fm didn't get so big because the founders spammed every single blog commenting system they could find, they became successful because they took the time to make something great aswell as using marketing skills to get their name out there. If you have to buy links to get anywhere, limit yourself to 5-10 at the maximum. The most effective tip I can give you is to limit yourself to 1,000 pages per pagerank. I've gotten listed on a huge corporation's website that is an 8 and came out with a Google pagerank of 5. So, your best bet is to get a sidebar link that shows up on every page, that way you have a better chance of getting indexed. However, don't focus on trying to get the highest rankings of your niche, there's going to be places where you can never get a link from, no matter how much money you throw at them.
This is absolutely essential if you want to start to grow a loyal base of readers. Social bookmarking can get the initial loyal readers for you in a short amount of time, given that your site has good content. To start out I recommend MyKillerStartup.com - Discover, Rate, and Share Killer Startups
Article marketing is also a good way to promote Your blog! If You regularly update your blog with good content that is keyword rich that will also give a lot of free targeted traffic.