I do it pretty much as Dun describes. I prefer aluminum wire to the polywire though. Tend not to have splinters and can be pulled tighter without stretching. Yet it is not as heavy as a reel full of steel wire. I like the P type step in posts. You will need a couple reels w gate handles so you can put up a lead cross wire then take the current one down.
I usually get the electric juice from the hot wire on standoffs inside my perimeter fence for the gate handle. I use #14 or #12 steel wire to make some loops at the tee posts on my semi permanent interior divider fences to hook the reel onto. Use a temporary non conductive handle in line with the regular gate handle, walk the reel up to wherever I am going to hang it, tighten the wire, walk back putting in P type posts (fast and slip over the wire easily) about every 10 paces to the other end, remove the non-conductive handle and I'm done.
I also like longer rectangular paddocks that I can advance a lead wire and not use a back wire at least for 4-7 days before they would start grazing the new growth. Broke the pasture shown up into two long paddocks with a semi permanent lane down the middle. They work from the camera towards the woods then shift over back again in grazing the paddock on the right of the lane. Lane gives them a path to water. All sorts of different possibilities at different times of year. They also use the lane for access to the woods for shade during the heat of summer.
I try to put them in when the growth is about 10" tall (but not stemmy nor gone to seed) and move them when they eat it down to about 4" tall. There are also lanes back to water. In the pictures below I will open the slinky gate in the right rear when they get to that point, put up a back wire and they will use the lane to get back to water.
Here are a couple pictures from a May rotation in 2010.
Jim
A before and after - ran the gate handle on the semi permanent in the picture, reel is hung on perimeter fence.
Patiently waiting. Rotational grazing really helps the legumes in the mix on the right
Next day will put in a back wire and open slinky gate in right rear so they use lane to water rather than coming back through what is already grazed. You can see the new lead wire reel hanging on the perimeter fence in the left rear. Just need to watch it doesn't hang in a way it shorts out to the barb wire.