Hi and welcome to the forum, Turner pens and anything eles can be as easy or as hard as you want. pen making its self is not hard, it is very straight forward, but you can then start to get a little more advanced with segmented stuff and all maner, have a look at this site lots of info on there for you about pen making, how to make them, jigs and all sorts related to pen making, http://www.penturners.org/forum/portal.asp
take a look at youtube as well as there are bound to be small vids showing pen turning.
Just think about what you might want to do as it can be expencive, lathe, chuck, chisels and a host of other stuff. so think before you go buying and then wish you had bought something better, no need to jump right in look around do your homework, lots of lathes are sold at different prices and it can be the same lathe but a different lable make on it, shop around use the internet.
Any wood can be used small branch stuff can be used for bottle stoppers, small turned boxes, if the grain and wood are plain then it can be stained, painted, pyro burn, textured in all manner of ways.
There are a few guys on hear that have more interest in pen making so you will get other help most like...have fun..LB