I'm looking for similar pages and sending a personalized email to their webmaters, inviting them to visit my site and include it in their link section.
My doubt is: should I include the description I would like to appear next to the link in the first email or should I wait until their response? what do you use to do?
It never hurts to include the necessary information so that their time is not spent emailing you five times to get the correct description, title, etc. The easier you make it for them to post the link, the more apt they will be to post it.
Remember is also good to put their link up first as a sign of good will!