hello selena…
i am workin in thz field from a long time….. i tried may books but all says only one thing you understand only those thing on which you practically work… my suggestion not to get strut on those books if you are really a begineer or really want to learn some somthing just go througth the tutorials given on the site links i am giving below they are very nicely explained… i went through them they are really very informative… select any one controller 8051 or AVR its upto you… all the best… and if if you have any query ask on the forum we will try to solve it…
what is microcontroller
http://www.engineersgarage.com/microcontroller
for 8051
wht is 8051 micro controller
http://www.engineersgarage.com/8051-microcontroller
tutorials:
http://www.engineersgarage.com/microcontroller/8051projects
for AVR
what is AVR microcontroler
http://www.engineersgarage.com/articles/avr-microcontroller
tutorials:
http://www.engineersgarage.com/embedded/avr-microcontroller-projects