1. Check using type default & how to selection configuration fuses. reading datesheet
like to following, infomation from ATMega48/88/168 datasheet
CKSEL3-0 : Clock Source Selector, default : "0010" (Calibrated Internal RC Oscillator), ref. section 7.2 of datasheet
CKDIV8 : default "0", so default CLKPR(Clock Prescale Register) is "0011", equ. divide 8.
SUT1-0 : Start up time, default "10", power on has 65ms+ 14 clock time to reset. ref. section 7.6 of datasheet.
so factory default setting of ATMega48 is operation at 1MHz, Internal RC Oscillator, slowly reset time
All fuse default setting has a table at section 26.2 of datasheet.
2. Programming tools
high voltage paraller programming
In Circuit System programming
3. WinAVR is a complete GCC compiler solution for AVR.it is free and easy use.