Gears- I am confused
 

O'K I am new to this stuff so is there anywhere I can go to learn about gears for touring. I am converting an old Raleigh Mtn bike for touring. Why can't I just use those gears? Go down if pedalling is tuff. up if easy? Will I run out of gears on each end.? With 24 gears how will I run out. Surely there is a happy medium with 24 gears

Youe transmission is fine, leave it be.
Most experienced tourists gripe that production tourers DON'T feature MTB gears.
I switched from a road triple to a Shimano LX MTB triple to get me up mountain tracks with luggage. Spinning out on big downhills does happen but it's not a problem.

Yes, as mentioned, mtb gearing is ideal in most cases. If you ever feel you need a little more top end, you can always swap your cassette for an 11T, if you don't already have that.
I built my LHT using 100% mtb drivetrain components, with a gearing range of 19~104 inches.

Not every mountain bike has gearing appropriate for touring, or for individual needs. I have a friend who owns a mid-1980s mountain bike with rather high gears. He has toured extensively on this bike, and it has worked well for him; but it would not work for me. He does not mind walking up hills. He pushes his bike up hills that I can easily drive up.

The gearing on your old Raleigh may be perfectly fine for the kind of touring you will be doing. You will know for sure after your first tour. The two most likely scenarios are that the transmission will be OK, or that you struggled hard to get up hills. It is less likely, although possible, that you want higher gears to bomb down hills.

If it were my bike, I would take it on day tours to determine what does and does not work about the gearing before replacing anything.

Acantor hit the crux of the matter right on the nail! That's good advice! Try it out and if ya like it, it isn't something that needs to be changed! If you don't like the result, analyze why and make changes accordingly! Speed isn't the key with touring, it's enjoying the ride! If you have the fastest geared roadie on the face of the Earth, and you detest riding it, then you've defeated the whole purpose of bicycle touring. To me touring is a solo thing...just me and my bike, and the world! I get to see things few others have time to notice as they whiz by! That's the whole magic of touring to me!