Any site that will teach you c# will help you with runuo "scripting"
There is also alot of info on this forum and on
http://www.orbsydia.com/index.php
I suggest getting some basic c# knowledge and just start playing around with existing scripts. Pick something simple like making a new robe, sword, armor, and try to tweak it. Change some settings. This is good way to learn item properties.
Try to make something like a teleporter that people can walk over and it does different things. This is a good way to learn if/else statements. You can then use the if else statements in your item attempts to restrict who can wear the armor or hold the weapons you scripted previsouosly.
Try to make a monster. Make it do different things, try changing its loot.
You can post your errors as you get them and many of us will help you along the way if you show enough of a good faith attempt to fix errors yourself.