Knowing how to properly store your comic books is almost as important as deciding which ones to collect. Here, I'll talk about a few things 1) where to put each individual comic book, 2) how to store the comics, and 3) where to store the comic books.
1) Where to put each individual comic:
Most collectors (and newbies, too), know that comics should be stored in an archival sleeve with a backer board. For my personal collection, regardless of the issue, I use archival mylar-D sleeves and acid-free backer boards. Make sure that these items are acid-free THROUGHOUT and not just "at the time of manufacture." Storing your comics in cheap bags and boards can diminish the comic's quality and, in turn, your investment. Personally, I use products from Bill Cole, Enterprises (http://bcemylar.com/).
For comics that are not for my personal collection (for example, comics that I'm going to be selling), I use lesser quality bags and boards. The ones used here are you typical bags/boards that are available from most retailers. For example, some can be found HERE.
2) How to store your comics:
Comic books should be stored upright and in boxes (like the ones shown in the picture above). DO NOT lay the comics down flat and stack them up. This tends to make the spine curl and the comic bend. It is not recommended to store them that way. Comic storage boxes can also be found from various retailers. Some examples can be found HERE.
3) How/where to store the boxes:
Comic storage boxes can be stacked, although I do not recommend stacking more than 3 boxes high. This can have the adverse effect of crushing the comics in the lower boxes due to the weight. The best thing to do (if you are able) is to build a storage shelf of some kind that can support and hold the comic book storage boxes. Where to build the shelf can be tricky though. It's tricky because most people use their basements since that's about the only place there is room to build. Basements can work for storage, but you risk the potential of musty/moldy smelling comics. Unless you are able to control the temperature or humidity of the environment (and protect them from flooding - a problem in some basements), I do not recommend storing comic books in a basement. However, if a basement is your only option, just make sure you can control the environment. A dehumidifier works well as does keeping the comics away from the floor (in case of flooding).