I've been an avid AVR hobbiest and developer for about a year ..... I just recently was put on the track of 8051/8052 microcontrollers and Maxim/Dallas Semiconductor

One of the things that separate the '51s from your previous endeavors is the plethora of derivatives that exist. Just have a look at the Keil device database

http://www.keil.com/dd/parm_search.asp

so di not limit yourself to one supplier because of free samples.

Another advice re "new to '51" is that there are a some derivatives (noteably SILabs) where you ger ICE functionality for free when you buy their development boards. And for seeing what makes a "new processor tick" nothing beats an ICE.

Erik