All links are not created equally. Some links can even harm your site. We strongly suggest that you hire a MN SEO consultant before taking on new site enhancement projects. But if you must proceed on your own here are some pointers.
Only link to sites that appear “non spammish” this includes sites that have over 100 links per page. Do not bother linking to sites that have poor page rank. It is better to just pay for quality links rather than waste time on linking to poor quality sites. Do not place out bound links on your site unless absolutely necessary and safe. externally linking to a spam site can get you blacklisted from google.