Personally, I think the north end of the beach is a little easier to manage than the south end, just because the climb back up the sand berm isn't quite so hard. But which end you do may depend on sea conditions. As somebody earlier mentioned, you want to go in at the ends of the beach. That means not just "not in the middle", but all the way at the far ends...like no more than 100 feet away from the end of the sand.
The first thing you should do is go up on top of the berm, sit down, and just watch for a while. It will take you no time at all to see why we are all telling you to go in only at the ends of the beach. While you are watching, you will see groups of divers come down the trail, go up and over the berm and enter in the middle. Quite often, they get trashed. It seems that every time I take a class to Monastery and take them up on top of the berm to give them my "Monastery lecture", there is a group of divers who do this. I have had students who were convinced I had staged this for their benefit!
When you get ready to enter, get your fins firmly in your hand and go down to the water's edge...and stop. Watch the waves for a minute or so. You want to time your entry for the calmest possible moment. Once you get it, head in briskly AND DO NOT STOP. Walk as far in as you can, then turn around and face the beach. You put your fins on while you are watching the surf zone so that you don't get pushed into it.
When you're ready to go diving, swim around the kelp; don't try to go through it unless you feel like you need the exercise. Once you're clear of the kelp, swim away from the beach. At either end of Monastery you will need to go out about 100 yards in order to get even 40' of depth.
When you're ready to get out, follow the above in reverse. Swim around the kelp, then swim parallel to the shore until you are within 100' of the end of the sand. Once you've picked your exit spot, move in until you can just touch the bottom. Get your fins off and move in a little bit more. Now watch the waves over your shoulder. As soon as you see a good one just about to reach you, start moving. That wave wants to lift you up in the air and then shove the upper part of your body forward. If you have your feet moving at the same time as it's trying to push you over, you will remain vertical. The net effect is that that wave will pick you up and set you down on top of the ledge in a standing position. It's all a matter of timing! Then you get to look over at your buddies who by now have fallen down and are rolling around in the surf and give them the expression of, "What's wrong with you? It's really all so easy!"
Bruce
