Just start at their recommended depth with recommended starting charge.  Once you do that, and don't blow yourself up, you'll have the confidence to start monkeying with things like seating depth and higher charges.

You need to read the manual and understand it.  For a starting load I would not exceed the maximum overall length that is listed and start the loading well below the maximum that is listed for the round.  Then after you see just what that load is doing you can play around with it some by changing the powder charge, primer, or seating depth.  You need to understand and be able to notice excessive pressure signs on the fired case and varying anything in the load from bullet seating depth to the primer can change the pressure of a fired round and should be worked back up from a safe load.   

Reloading is a very fun and safe hobby but you need to understand that you need to take care that you do it right.  If not you may be buying yourself a new rifle after the outcome or a bad load.  The best way to explain it is that you are making a bomb but one with a controlled and confined explosion. 

I'm gonna vary from what the guy's are saying a bit. If you look in different books you'll notice that that length changes and none of them have any idea what the length of your throat is. What you want to be sure to do is to keep the bullet back off the throat and still fit in the magazine well. It could be that your magazine well will determine the OLL of your cartridges. But then again it may not. Easy way to figure out where to start and that is to measure the distence from the bullet tip with the bullet tip touching the lands, to the base of the cartridge. When you do that, keep in mind that you need to use the same bullet to set the die that you will measure in the throat. And that case with that bullet needs to fit into your magazine well.

Close the bolt on your rifle and run a cleaning rod to the face of the bolt, have a plug on the rod to cover the opening. Now take a pencil and mark the cleaning rod exactly at the muzzle with a line across the rod. Next remove the bolt and drop a bullet your going to load down into the throat of the barrel. drop a long pencil, eraser first, behind it. Hold the bullet into the lands with the pencil and move the cleaning rod to the tip of the bullet. Mark across the rod at the muzzle again. Next measure the distence between the two lines and if you load the round to that overall length, you'll have the bullet touching the lands. I don't care for that so when you get there, screw the die down another 1/8th to 1/4 turn. That will back the bullet just off the lands.

The reason to use the same bullet to measure and set the die is that bullet length will vary somewhat. What you need to do is be sure the ogive of the bullet is just off the lands. That ogive will vary to some small degree on each bullet but, the seating die will contaact the bullet at exactly the same place in diameter each time it seats the bullet. That is the important part to keep the bullet off the lands. If you want Hornady makes a tool to measure the distence from the bolt face to the lands. I don't believe it's necessary though if you follow the instruction above. What you won't be able to do is tell what the seating depth is to the lands. What you can do is load that first bullet to set the seater die with in an MTY case and save it to reset the die as needed for that bullet. That OLL with that bullet will always be right and with the same bullet will never change.