I'm about to start the very first link building campaign ever on a 6 year old high PR domain/site that I have, but I only want safe backlinks that won't come back to bite me in the ass later down the road. That said, the links need to be effective, authority links. I've got some advice that guest posting isn't that good for short term seo benefits because the page my post is on will be a PR0. What types of links are effective but not spammy looking to G? If I'll get punished for the links later on, I'd rather do nothing. Thanks in advance for your input.