Originally Posted by AlbertZeroK
You can look up the paper manufacture's recommendation for paper development.
You don't want to leave the paper developing in a tray too long, usually 1.5 minutes in Dektol 1:2 mixture. This would be for your average B&W print. Different papers react differently to exposure and development times, much like film does. There are some different printing methods and developers that use different starting points and dilution recommendations. It all comes down to what kind of prints you want to make. Your paper choice, developing chemical choices and how much or little you dilute your developers.
There are some great darkroom technique books available that can give you a good starting point. One series of books comes to mind, Saint Adams series books; The Camera, The Negative, and The Print.
Don't worry about making mistakes, sometimes those mistakes can lead to some great prints.