I just checked out your site, http://www.mujzune.cz/ , it looks very nice, good job on the skin design!
One thing I want to caution you about since I see you already have a lot of content in your blog. If you move your blog from the home page its going to break all the friendly urls for your blog posts and the friendly url for your feed, but you can fix them. For example your most recent post has the url "/video-zune-marketplace-a-virtualni-klavesnice.aspx" but this friendly url really maps to /BlogView.aspx?pageid=x&mid=y
Currently x = the pageid of the home page so if you move the blog to its own page those urls won't be valid. You can go into Administration Menu > Advanced Tools > Url Manager and find the url mappings and fix the pageid to match the new page.
There is also a friendly url for the feed /blog4rss.aspx that will also need a correction for the pageid after you move the blog.
Hope it helps,