From the extremely small amount of fiddling I've done with LUA plugins for the game (wrote an extremely basic context-sensitive quickslot bar during one of the first LUA betas) it's closer to C++ syntactically. I'm a VB.NET web dev myself, and if you're comfortable with Javascript or curly-braces in general and basic OOP design, LUA's not too difficult. I'd recommend taking a look at the source for some existing plugins and some of the wrapper/extension classes that others have made available here and on the Lotro forums (things for Ctrl-\ window positioning and the like).
Start with something basic. Just creating a windowless "listener" class that will listen for certain events (entering combat, leaving combat, dying, etc) and output some text to the chat window would be a good start. Once you're comfy with hooking into the event API you can then start playing with quickslots, equipment, and new UI elements a little more comfortably.
Good luck, and happy developing!
Hopefully some others can provide much more in-depth and sagely advice than I