Well, it is kind of hard to pick up at first, practice it for a few hours and you should have it down though. As for welders, get a MIG, you will thank yourself later. As for welder voltage/power, it doesnt have to be great. Pretty much anything will do.
If your high school has a welding class, take it. I did at my school, and the entire semester all I did was build different types of rails. It's not that hard to learn, it just takes practice.
my dad welds for the us navy at a nuclear power plant here....they buy him anything he wants to use their...i have him do stuff...im right now planning the largest trap rail ever
get either a mig or arc welder, but i personally like a wirefeed welder. I have a hobart stickmate which is their basic welder which costs 300 dollars but u need to buy a special plugs cuz it uses a lot of elctricity
if your a first timer then go with MIG, its alot easier and faster then a TIG welder. TIG will take a longgggggggg time to weld up an entire rail if you have never tig weld before, trust me. MIGs are fairly inexpensive and are perfect for tacking up pipeline. TIG is more for meticulous and precise welding work.
Why would you ever us a TIG welder?? Use wirefeed or arc. Wirefeed is the easyest and its damn strong. (to anyone whos welding now because this thread is 3 years old.)