Golden Age I was advised many years ago to spend as much as I could afford on the best condition books. That's great advice but I didn't really follow it because I'd only own about 20 comics now if I had. I always tried to get as many books as I could in F/VF or better with however much money I had instead of blowing all on one book. This was pre CGC days so paying many multiples of guide wasn't usually a problem like it is today.
You can't go wrong buying DC and Timely superhero titles. All other companies are 2nd tier and I would say Fiction House is 3rd tier (Planet is cool though). I always prefered anthology titles over others: Flash over All Flash, All American over Green Lantern, Marvel Mystery over Human Torch for example. That's just me. I like the variety. The most valuable comics have always been Action #1, Marvel Comics #1 and Detective #27 - all anthologies. As much as I like titles like Speed, Startling and Thrilling, I would stay away from those for investment purposes. Stick with DC, Timely: Action, Detective, Marvel Mystery are proven winners. Nothing wrong with All Star, Adventure, Mystic, USA, etc either. Sounds like you're going to have FUN!