Start off by searching for blogs that share interests and keywords with yours. If you're feeling picky, then a popular blog would be a tad more worth your time. You have a choice now if you want to follow them or not. Some people like to save their follows for only those they find most interesting. After this, find a post that you can comment on. Be friendly, show some interest, and if you're subtle about it, maybe mention your own blog.
This is the magic of blog networks. It's almost like the theory of Nash equilibrium. Instead of all the blogs competing for visitors and in the process losing some, build relationships with your competition so that everybody can benefit.
