I want to share these resources with you. You can check the same at http://www.bestdesigntuts.com/20-best-social-bookmarking-resources-to-promote-design-articles/
Why you guys always think about dofollow or nofollow. Main things about these resources are, you could get some great exposure by publishing your articles here. More exposure you get will give you chance to be linked with other blogs as well.
In terms of SEO, no follow links are not that great as it do not let crawlers follow your links, so these links do not add value to your SEO process.