Fairly basic set. Use it as a lead to set up hazards, and as a Rapid Spinner.
To get Forretress to learn Stealth Rock, breed it it with compatible parent that can learn it, for example, Dwebble. Dwebble learns SR at LV 26. Here's what you do:
First off, the baby Pokemon will know its LV 1 moves first. Overwriting that are the LV up moves, moves that can be learned by LV up that both parents know. So let's say, Dwebble knows Bug Bite, and so does Forretress. The baby will know 3 LV up moves, and Bug Bite. Of course, Dwebble also knows Stealth Rock, and so that will be passed down too. So you will end up with a baby Pokemon with Bug Bite, 2 LV 1 moves, and Stealth Rock. You see?
Here's a quote from our breeding section:
'If there are too many candidate moves that the baby can learn, they follow this precedent, with each new move overwriting previous ones:
- Level 1 moves.
- Moves that the child learns by level up, if both parents have them.
- Any compatible TMs, HMs and move tutor moves known by the father.
- Any egg moves known by the father.'
Hope this helped. And please note, if this is Gen. 4, Forretress can simply learn Stealth Rock via TM.