I have a Catalina 22 and I have this deal that i bought with the boat its a 6 foot steel pole with an open block at the top. It is attached to the fore part of the trailer and when raising the mast I have my genoa halyard fed through and attached to the trailer winch belt. One person helps raise the mast and steady it while the other winches in the halyard and up goes the mast.
However, I make it sound easier than it is. Frankly put raising the mast is a bitch. Especially if you have a furler. If you have a furler, it is very difficult or atleast I find it difficult since the stay always wants to go back in to the furler. You need atleast 2 people to raise a mast and three would be best. Take great care that your aluminium (im assuming) mast step does not get damaged as you raise.