A blog carnival is a collection of links pointing to blog posts around a specific topic. Usually a certain blog carnival will have many editions, and every week a different blog will host it. In order to participate all you need to do is to browse around the Blog Carnival website looking for relevant topics and submit your entries.
This is a simple yet effective method to promote your blog during the initial months. The carnivals will bring you some traffic and some backlinks. Additionally it will also give you the possibility to interact with fellow bloggers.