ISP - In Serial Programming (very useful thing, you can programming your microcontroler on board, without taking microcontroller out, put in programmer and back on to board)
JTAG - I do not know what this acronym mean, but that is programmer too, but you can and debug with them. If you like to read, I propose to you to read Atmel JTAG ICE User guide
There are numerous development boards available in that price range. Selecting one would depend on availability in your area. Another option would be purchasing a STK500 from Atmel or distributor. The STK500 has a builtin ISP programmer and supports many of the AVRs in DIP packages. The STK500 was replaced by the considerabily more expensive STK600, but apparently is now once again available for purchase:
ISP, In System Programming, is Atmel standardized way of programming a MCU while installed in the circuit. JTAG, Joint Test Action Group, also has this capability as well as offering In System/Circuit Debugging as well. The JTAG debugger feature can be quite advantageous when developing new application code. Of course the JTAG programmer is usually considerably more expensive than the ISP programmer.
my question is this kit is good or not as iam beginner and i need your help to take decision about this kit and if this kit is expensive can you recommend me another one ?
AVR devboard you can perfectly make on your own. Either fully homemade pcb or manufactured by a pcb company. AVR is kind low speed, no "difficult" packages involved (like qfn or bga) so pcb design is really simple. This way you will get to know other aspects of microcontroller usage (other than programming).
Maybe I will not help you a lot with this answer, but when you ask which microcontroller is better, nobody can give a simple answer. If you want to develop some comunication applications simple chose what type of communication you want to use (RS232, RS485, USB, ethernet, RF, wireless, zig bee...) and try to find microcontroller which has support for that type of communication.
Or, you can use some regular microcontroller, like Atmel 8051, ATmega16, ATmega8, and interface microcontroller with some communication module. That is easier way if you must solder alone that components, because that type of microcontroller you still can find in PDIP packages.
I hoppe this will help you. Tell us which type of communication you plan to use, and maybe we will able to help you more.