My best advice? Don't buy anything because you expect it to be valuble. It likely never will be. If you're going after a complete set of something, buy lots - be patient - expect to get duplicates and sell/trade for pieces you're missing.
Also - DON'T go for a complete set of anything if you're just starting out. That's the best way to get 300 garbage NES titles and waste a lot of space
Trust me, I know!
Start collecting what you want to play/have based on nostalgia or taste or whatever. Figure out a theme for your collection if you have no idea where to start. For example, I like SMT games. I have most of them because I like them. None of them are that valuable, but I feel good everytime I pick one up. I don't regret purchasing any of them.
A lot of people say that being patient is important. While I don't technically disagree, I will say that you should be ready to pick something up if it's on your shortlist. This is especially true if you're concerned about condition. If you're just starting out, I would recommend that you choose your condition requirement from the getgo. If you don't mind a torn label? Fine. Just don't pick something up with a torn label expecting to replace it later on. That only sometimes works, and, if you care, you'll end up with multiple copies of potentially expensive games that no one really wants.
I could keep rambling, but I think you guys can pick out of that. I've been doing this for a while. If you have any specific questions I'll answer them.
EDIT: For the love of god, don't freak out over CE stuff. I collect some of it, but some of it is utter garbage. Most of them end up being on Amazon for half the asking price when they're new. Unless you actually want the game that comes with that statue? Don't waste your time. Just my opinion.