First make sure you are running arduino 0.22 or 0.23 and then:
Make sure that the drivers has been installed for the board. In Win7, Go into start->programs-> admin -> computer management and make sure that there is no "unknown" under ports, or anything with a ! or a yellow symbol. If there is, then read the step to install drivers manually, basially pointing the drivers to arduino022/drivers (my money goes on this beeing the problem, new versions of windows should fix it but have had to do it manually on win 7 enterprise..)
If this is ok, then you should see what port the board is using and use that one in arduino. If all this is aleady ok, then make sure the right boars is added and selected in the arduino gui.
I dont have to press the reset button, but you should try both, first of not pressing it. A upload takes about 45-60 seconds for me, and you dont get any feedback before its done.
http://www.ladyada.net/learn/arduino/help.html