Buy links at high PR, or submit to HIGH PR directories. I think you posted this in the wrong section anyway.
Submit real comments to blogs, submit your links to directories and use also the links on the forum signature Easy, fast and cheap
Read up the previous threads in the seo and link development forums. A google search wouldn't hurt either. Next time you have a question, use the search function to see if it's already been answered. Ah, and make sure it's in the right category.
Funny qyestion PR is NOT IMPORTANT is just a number (influenced by backlinks) You should concentrate on rankings
PR is not very important for rankings but it's nice to have. Those who study PR believe it to be base 8. Which means that it would take like 8x8x8x8 PR 1 links to give you a PR 4, 8x8x8x8x8x8 PR1 links to give you a 6 and so forth. But it only takes like 8 PR 7 links to give you a 6. It works out something similar to that. That's why if you care about PR, just buy like 8 links from really high PR sites. I don't recommend it though, unless your whole business is to sell links to boost other people's PR
you need backlinks from high pr web site but nobody can give you exact number about how many backlinks you need