Pagerank 3 is a pretty low target. You will not have problem to get this kind of pr. Generaly link exchange is not the best option as it might lead to pagerank loss. Ask from friends or colleagues to add a link to your blog. Also you can try to create more links by submitting your blog to relevant directories, try the social media, etc. If you have very few links that point to your site you could use a automatic site submitter, but generally keep in mind that this kind of tools will not help you much. On the other hand if you create good quality content that people find it interesting and if you update your blog often, you will get more quality links and this will lead to the pr 3 that you want.
be careful with link exchanges - many sites' PR has been reduced to N/A since yesterday - i noticed this in many web sites and they were all doing link exchanges.I think that Google is going to be more strict with sites doing link exchanges.A PR3 can be attained with just doing the blog directory submission - i have done this earlier and got a PR3 without any hassle.
You can also comment on a dofollow blog rather than trading link, in this way you can get a clean one way dofollow backlink. But don't comment spam ofcourse..
that is impossible! To get a good pr you have to keep doing SEO on a constant basis. You must do article directory submission, forum posting, blog commenting and so on.
You can get page rank 3 by link exchange and also by submitting your blog to high page rank directories.