Hi champbc and welcome to Webmaster World.
Digimon suggestion is certainly valid. Personally though I like my links spread out on the site, helping to raise the PR of the individual pages, which appears to help bring up the rank of those internal pages. Internal pages are usually better optimized for a specific keyword/phrase and raising those pages PR seems to help move them up to where they can be found in a search. I believe this is good for the site, for the searcher and for the search engine.
I think it was Brett that suggested it was better to get 1 visitor a day on 50 different pages then 50 visitors to one page.
Also, besides the keyword optimization of the internal pages is the content. I prefer to link relevant content to relevant content. I found this is a great way to encourage linking. Instead of asking for a link to your home page, ask for a link to content that relates to their site. This can act as a way to add to their content, in a roundabout way.
With linking I personally think not only of the PR and Google, although that was the main point of your question, but how this link will add to the site and to the visitors experience.