Doubt in User Exit

Hi experts,

Plz tell something of user exit bze i am new in user exit...

1. How to search user exit in SPRO path.

2. Wht are tha varrious ways to find the user exit and how?

3. How to find the particular exit suitable for this particular prgm, bze for a single tcode contain lots of exit prgm so how to find?

Plz help, point will be sure...

Regards,

Gowri