What etymology dictionaries are available? What dictionaries (online, software-based or in paper form) explain the origins of a word and its evolution over time? E.g. how the character was once written, how the usage – and the meaning – changed over time.
Wen Lin is an amazing piece of software that has all of the etymological features you are looking for. The central downside is that it is a bit pricey. Most universities have a copy, though, and there may be the opportunity to get some kind of student pricing discount. (Not sure if that applies to your case.)