What i like to do is go into the big stores that have them set up on display and try them out see if the keys feel comfortable and the screen is easy on your eyes...

take a note pad and write down the model # & price at that store of any that you like - then go home and check prices online - some times the store will match the online price for a sale if you print it out and take it in as proof.

You can also look up reviews on the model/brand to check for known issues.

I think all laptops now can do anything a desktop can - unless you have some specific need or older software that you use.

stick with the main brand names and you should be fine.
here's one site with reviews-
http://www.consumersearch.com/www/computers/laptops/