I have a small flock of laying hens, no roosters. Let's say I wanted to breed one of them. Do people actually take hens and roosters back and forth for breeding like dog owners do?
I would not do this for biosecurity reasons. Either flock could have something that they are immune to but can infect the other flock. Coccidiosis is a great example. But, yes, some people do mix flocks. Usually, it is not a problem, but sometimes the results are disasterous.
I would guess if I stuck my hen in with some strange rooster she'd probably get beat up pretty bad.
That just depends in the rooster and the circumstances. Usually the rooster is glad to accept another hen into his harem, but the hen has to find her place in the pecking order with the other hens. The rooster is probably not going to be your problem. It will be the rest of the flock.
Where I live I simply can't have a rooster. I really got the girls just for egg laying, but a batch of chicks someday would be pretty cool
If you hatch eggs, you will get some roosters. You need a plan to handle that.
I agree with some of the others. Unless you have a specific reason to want the eggs to come from one if your hens, I'd strongly suggest getting fertile eggs. The best source is someone local where you can pick up the eggs, not get shipped eggs. You may already know a local source. If not, you can find your state thread on this forum in the Where am I? Where are you? section, talk to people at the feed store and maybe put a note on the bulletin board, talk to your county extension agent (in the phone book under county government) or put an add on Craigslist.