You can easily achieve good pr, but its hard to achieve good serp's. As google says, dont build site for search engines build it for users.
As mentioned before, there are no shortcuts. For solid long term PR, start off with creating a fair amount of high quality content and then spread the buzz around through social networking and then create more content.
build a ton back link with link exchange, but it will mess our blog for ton outbound link too. Yah, there are no gain if no pain.
Bascically, there is no easy way to improve PR. The process has to be hard and time-consuming, and plus no one guarentee your results. Maybe, start with a little bit quantity work will worth it. Because, you backlinks are directly proportional to your page rank, as whenever, Google updates the PR, it will distribute some amount of PR to the links lying on a page.