This is pretty simple if you use firefox install the SEOtoolbar for it, there is a button you can turn on which highlights all nofollow links. So then you know a link is dofollow if its not highlighted. Just google for the Firefox SEO toolbar, it also has lots of other useful SEO tools its very good
I use the FireFox add on. Turn it on, any comments that are no follow become highly visible in red highlight. Find those, leave the page and find another blog that does follow.
There are plenty of dofollow blog lists floating around. Just search Google for "dofollow blog lists". I don't think there's any way you can just search for them.
I've used fast blog finder. There is a free version that limits the amount of blogs it finds. It's the best software I've used to find dofollow blogs.
Make a search "fast blog finder" in google and you will find a sofware that can find you DO FOLLOW blogs with their Page Ranks, if you download the free demo version you are only allowed to get 50 blogs at a time. But you can also search for different keywords and find more. I hope this helps
I use SeoQuake and mark in it "line trough "nofollow" "noindex" Also it shows page rank of the downloaded site..Fast blog finder is great but it costs 50$
Tested Fast Blog Finder: Showing 50 results, 2 blog is dofollow, but when I tried comment then it shows NOFOLLOW
SEO quake is very useful does slow down your search results a bit but guess you have to comprimize a little
there is an easy way to find out links that are do follow..why not try NoDoFollow :: Add-ons for Firefox?
I just bought the Fast Blog Finder and I think it's great. It's much better then using Google and SEO tool bar in Firefox. Much more professional I recommend that you people try it.