What are signs to look for in mating fish?

So i have no idea how exactly fish mate, so i'm not sure if my clowns are just constintly poking at each other or if these are signs of possibly mating? I got these two black and whites as a pair, the female is twice the size of the male. I've had them for 2 1/2 weeks now, their currently the only fish in the tank. First week they acted perfect, now they are constantly going at each other, nothing bad or anything. And it's both fish poking at each other, mainly by the mouth area, and swim under each other's belly.

Another thing, when their not fighting they like to sometimes swim right in front of the powerheads and play in the current, they also swim all about the tank, pick at rocks and sandbed, even though i have no copepods. And they both twitch

Could they be possibly trying to mate, or is this just normal fighting?

 

Marine And Saltwater Fish: Breeding Clownfish
I hope this helps your situation.

 

I would say its a good sign that they are pairing up. But it may take awhile to see if they spawn or not.

 

This article has a good section on clownfish breeding
Advanced Aquarist's Online Magazine - Aquarium Fish: Reproduction and rearing of ocellaris clownfish (Amphiprion ocellaris) in captivity.

 

thanks all, i'll make sure to check out the sites