To stay safe what I usually do is build some Good web 2.0 links then build hundreds of links to those links so that the link juice will filter through.
If there is a limit, it's so large of one there's no need for you to concern yourself with it just yet.
I have built thousands of links per month with no penalty. the only penalty I have had is running adsense on autoblogs, when adsense quality control took a look they banned 17 of my sites, the other 50 or so were fine. The only sites I had banned were ones running adsense.
I don't think you can get to many links and there's a general misconception that, you'll get penalized by Google and the other main search engines if you create to man links over a certain time period. If that was the case then, yell, thomson and other article directories would fall in to this category and that just isn't the case. I always look for high PR links from websites that have forums who allow anchor text in their profile areas. Mark
On some occasions social bookmarking can turn against you. Suppose you happen to post links on a site that lead back to your own website you are bound to suffer of the same penalty that befalls that site.
These is no count of Link Building for your website. There is no too much link until you can not get your website top in the Google.