Good article for anyone just getting started on Link Building published on WebProNews.com. This well thought out article by John Krycek, of MouseWorks, covers the Linking Strategies: Dos and Don’ts.

The part about keyword variation cannot be stressed enough. Think organic. Think natural.

Step 2- Create variations on those keywords.

Think of phrases that someone might enter into a search engine. Using that thought as the core, build outward by elaborating and specifying. Ask yourself “what type of ____?” to help you expand. For example, take the few keywords above and make them a bit more specific to:

pumpkin pie recipe
pumpkin bread recipe
cooking pumpkin seed
pumpkin patch
how to grow pumpkin
planting pumpkin seed
pumpkin carving design
carve Halloween pumpkin
pumpkin carving pattern
pumpkin costume
pumpkin centerpiece

Here are some of the tools I use daily to come up with keyword varations:
http://www.kwmap.com/
http://www.gorank.com/seotools/ontology Tool
http://thesaurus.reference.com/

Every now and then hyperlink the URL like I did above for the tools. Or maybe use “Click Here”. That way your site will appear more natural and less SEOed.