You'll get as many different ideas on breaking calves as there are people who've ever broke a calf, so I'll tell you what we do (and we're just now breaking some that'll start showing in early August, and a couple of 'em are sure 800+). We'll tie them first in the working chute and the alley coming in to it - they usually don't fight the halter long at all when they can't move around much. You can pet/brush on them, talk to them and make friends with them while they're confined enough that they have to put up with it and it's safe for even the smaller kids to mess with them. We do it for just 30 minutes to an hour, and feed them soon as we turn 'em loose. Do it at least once a day, but make sure you do it every day. Usually after 3 or 4 days of this, we'll tie them to the fence - some will still fight it a little, but not nearly as bad as they would've if you went straight to the fence. Again, just for an hour or so, right before feeding - we'll start getting them used to the show stick now, too. After a couple of days we start leading them to feed, soon as they start leading halfway decent, lead them farther before you turn them loose to eat. In a week to ten days, most of them are going pretty well. I know a lot of folks like to try to break 'em in a couple of days, but this way is a lot less stress on cattle and people both, IMHO.
I used to like to tie them with innertubes, because there's some give when they fight the halter. It worked well, but old innertubes (that are still in one piece) are getting harder and harder to find.