The correct use of anchor text would be:
Your Keywords
Use the actual search term that you want to be found for and that you are optimizing the page for.
Try to link with sites that like you said your visitors would be interested in, or relate to your site, but are non-competitive. You have every right to turn down a link request, and very often people use programs to send massive amounts of link requests to people to quickly build their incomming links. The best way is to review each site, and ensure that :
1. The site is good quality, well maintained, and provides usefull content.
2. The site isn't banned by google or any other search engine. I would either make sure the site has a google Page Rank of at least 4, or you know the person that you are linking to.
There is absolutely benifit from a PR3 page. Although it is not as high as a higher
PR site, if it is a related website, the owner should take into consideration that you are building links, and thus your
PR is going to be going up.
I think you have a very good start on your links page. The sites seem to be relavent and of good taste. There is nothing that would even suggest that you are trying to link to anything but a usefull site. One thing that may be an issue in the future is that the descriptions are long, which is fine, but when you get a lot of links there will be a lot of scrolling required to get down the page. When you have a lot of links on the page, where it is getting pretty long, I would make a second links page, and link it from the homepage just like the current links page. This way it too will have a good
PR from the start.
I hope this helps some,