Ahh... this is one of the common issues people face with building backlinks. Generally any link from a decent site can be considered a good link no matter it is follow or nofollow, which ever way you look at it. Search engines like google likes to look upon highly on websites that does link building on different IPs. Also consider your internal link building. Having link juice from incoming links is as equally important as building your internal link structure.
Building links does not require you to have lots of links from forum profiles or exchange links from other people, what is important is whether your links is relevant. There are many webmasters that are trying to cheat the search engines therefore not all links are indexed. Also, ranking factors are not just from backlinks alone, a brand new website with the right onpage factors and keyword you can literally rank top 10 within days only with just a few good links.
Lastly, what the search engines wants to see is not too much on how many backlinks you have because spam is very popular these days, however that is a good way to determine whether or not you have any authority on the given niche, what's important is that you know what you are optimizing for and how you are linking to it.