Someone by the name of Nash has given a good list of dofollow blogs on this same dpforum. In warriorforum someone by the name Angela has a good membership service wherein she provides list of 30 high pagerank sites with dofollow links where you can get links to your site. Each month you can get a list of 30 such high pr sites. The cost of membership is really affordable at $5 per month.
I think one of the best ways to find dofollow blogs is by using softwares like fast blog finder. Great tool and finds a lot of results with the paid version.