There is no intervals in linkbuilding. Linkbuild as long as you got time. But don't linkbuild outside your niche. its better to keep your links related to the forums or blog.
On the weekends I generally do not Link Build, will that hurt my page rank? Also are building links relative to my niche a necessity?
I try to build 10 - 20 a day, mainly through my forum signatures and posting articles on my various blogs. On weekends, I might do 10 new links over the course of saturday and sunday. I have had negative results from getting too many links in one day. On a certain forum, I have around 500 post. One day I added a link to one of my blogs to my signature in that forum. That gave the site around 500 new links over night. The result - the blog was knocked out of the Google Results Pages. The blog was ranking between page one and page three in its targeted keywords. But after adding those new links, the blog disappeared for a couple of weeks. The site went from page 2 or 3, to past page 30 - because that is where I stopped looking at. Link building should be natural and that does not mean several hundred or even a thousand links a day.
According to me link building in a single way would be more safe and effective rather than a 2 way linking method
Really, I think your best bet is to initially get the search engines to recognize you through forum posts. Then find REAL links, what I mean by that, is links where the page on the link has a KNOWN PR, and it is do-follow. So if you get a link on say, a website's main page, and they have PR3, this is very valuable.