General informations about network shield.

Hi everybody at first, I apoligize for my poor english :) I don't even already have an arduino but i gonna buy one. I enjoy to make some pc remoted device like camera turret or things like that... but since now i used two computers one to remote and an other to receive commands and then to communicate commands through serial ports to my microprocessor. But now i would like to do smaller things so i cant have another "embed" pc anymore... So i would like to learn a little bit about arduino wireless communication solutions...

WIFI/Bluetooth: how does it work? do you program the arduino board with sockets like with a pc and the arduino will run his librairies to use the shield? do you directly program the shield and the transmit received datas to the board via serial port or something?

Radio? is there any shield witch allow you to use your arduino as a radio emitter like ones used for rc cars? is it possible to change the frequence by changing the quartz?

I know thoose questions are very wide but i need basicly informations to begin to search more specifics.

Thanks a lot, i hope you will understand my english :)

Some thoughts on a simple arduino based routerbot.

hi, i am sorry to disturb you for a such begginer question... I would like to know if it's easy to use a wishield 2.0 with an arduino mega? if i take the blackwidow, and use wifi on my program how many digital exit does it left ? how many pwm? and how many analog? Thank's a lot.