lol, sorry for the laugh but the PIC doesnt need a bootloader. Some pics dont have bootloader capabilities at all. MPLAB has nice Simulation and many other simulation tools for PIC are available. Most if not all PICs have ICSP (In Circuit Serial Programming) and ICD (In Circuit Debugging).
ATMEL is wierd as they have many different programming methods for various chips like JTAG, ISP and many more. Which may confuse a new user. PICS only have ISCP.
PICs are by far better starting point for beginners to jump into the environment.
EDIT:
Note to "vinoth" what PICs are you using that you need a bootloader? Parallex? or maybe you dont have a real programmer so you use a bootloader instead?
If you own a PICKIT 2 or a Junebug(is awesome!) then you are good to go. No bootloader needed.
Check out :
I own that and a PICKIT 2. I had the junebug first. Its awesome to learn on and very cheap and can be used to program many if not all other 5v PICs and with a slight mod the 3v PICs also.