Be aware -- fish-in cycling can take several months to complete, and sometimes you lose fish in the process no matter what. The safest way is fishless, and it usually takes less time.
If you want to do the fish-in cycle, I'd suggest picking a few very hardy fish to start off with. Do you know what type of tank you'll be wanting to have? Do you know how many fish you would like to have in it? Smaller fish will allow for more in quantity, and larger fish obviously not so many. You also have to account for some space taken up by your decorations and plants.
I would start off with no more than 3 fish in a start up. Zebra danios, White Cloud Mountain Minnows, and some types of tetras such as the lamp eyed, tend to be pretty easy starters and can make up pretty cool looking schools. Platys, Mollies and Guppies are hit-or-miss. For the most part they're sturdy, but I've read that the guppies aren't as hardy as they used to be at least 10 years ago. Over breeding will do that to anything. I believe tiger barbs are pretty sturdy starters in the semi-aggressive category as well, but you should be watching what you add. Tiger barbs should be in a school to limit the amount of fighting, and most tetras should be in groups as well.
You kind of have to put forth some planning. I would not suggest putting fish in just to cycle the tank for you, and then realize you don't even like those kind of fish later on. Some very unfortunate people choose to cycle their tank with goldfish or giant danios and then are saddened when they realize they shouldn't add any more fish into the size of the tank they have because they chose "big" fish, with perhaps more maintenance than they bargained for.
I would also pick up a good water conditioner such as Seachem's Prime, which will help lessen the stress of any ammonia, nitrIte and nitrAte spikes that are going to happen in your tank. Adding it any time you do a water change should help a lot. Adding a lot of OXYGEN will help the cycle go faster (not to mention AWESOME for your fish); a lot of water changes (every few days) and surface disruption (filter and bubbler). It may be a pain in the butt, but it's worth it in the long run!
Some people will add Bacteria supplement to their tanks, and that's OK. But personally, I don't know how much good it does unless the bacteria they get has been in a cold place. Most products sold on the shelf aren't, and they sit there for a pretty long time. You may be lucky enough to have some bacteria alive at point of purchase.
