If you are doing your link building manually, then you probably won't be able to make google see more than an average of 20 links per day. This is due to 2 factors:
1) Google sometimes rejects a link entirely because it doesn't like the source. This is reflected in the huge differences between the backlink reports of backlinkwatch.com (yahoo) and google webmaster tools. The latter almost always shows fewer backlinks for your site.
2) There will be an indexing delay for all backlinks. This can range from a few seconds to several weeks, and tends to smooth out the rate at which Google registers your links.
As for the best build rate, It's not as simple an issue as other posters here are making out. Sure, you may well be safe if you try to be consistent and as a rule it's best to try and keep things that way.
However, I have had success with one site which had 2 weeks intense building, 1 month stop, 2 weeks intense building, 1 month stop, and the same again. It was sandboxed for a few months but now it's doing great and I haven't sent any links to it for 4 weeks now. There are exceptions to the consistency rule. Google's algorithm is complex and you never know what you're going to get. I tried very consistent building with one site and it has yet to show itself in the serps.
The point I'm making is that consistency seems to make sense, but even following this rule will not guarantee you success in the SERPs.