Maybe I am too old and certainly conservative, but I am simply fed up with the computer stuff. I find the IDE's too complicated and hard to learn. I know, creators of the IDEs try to pack them with features, but it'still those uniform windows - flat and boring.
On the other hand, I always have been fascinated with a working piece of hardware - even the simplest "blinking LED" one. And, what is even more satisfying and inspiring for me, is when that hardware obeys my commands!
I prefer to take a piece of proven working hardware with some basic test routine, then try to modify it and see how it behaves.
You could perhaps start with some of the modern serially (meaning generally, not restricted to uart) downloadable clones of 51, being it Atmel's 89S5x (for which download sw can be found somewhere in the users pages on this site), RD2 of Atmel or Philips, or the LPC9xx line of Philips - anything you get.Glue together a simple power source (7805 etc.), a max232 or clone for level conversion, a crystal and the micro - use a protoboard. Or maybe you can buy some ready made testboard - get the very simplest.
Try getting some example, e.g. some simple serial echo. Translate it to hex form using the simplest tools you find - some basic 51 assembler maybe. Download, run a terminal program and enjoy!
Then you can start modifications - monitor input pins and send their state to the serial periodically, light LEDS according to commands received from serial. Then try the timers - try writing a clock (clocks are fun). Etc.etc.etc...

The key is to keep it as simple as possible for the start, and... to enjoy yourself!

Jan Waclawek