I have a website for my private practice as a psychologist and have written several articles tor the site that I think would make good magazine pieces.  The site is designed for local attorneys but I have a few pages for the general public.  My site is rarely if ever visited.  What rights am I entitled to sell?  When do I mention that the piece has appeared on my website?

I'd mention up front that the piece is on your website. Some magazines, especially online ones, won't touch something that's all ready published online. You retain all rights to the work. The only one that may be in question as far as republishing is First Electronic Rights. This comes into play if the magazine publishes online or both in print and online. You need to check the guidelines for the specific magazines you wish to submit your work to for their specific policies on this.