"Just say NO!" Unless you are in need of a habit that consumes all your spare time and money!
The bigger the tank you get the more diluted any mistakes you make will be... So I would recommend starting no smaller than 55g... I have heard many on here that really like the 40g breeder size tanks though. If you want to save a lot of money skip over the whole canister filter phase everyone goes through and just start with a sump (kind of a big step for a newb).
So there you go... tank and filter solved. Now you have to figure out what kind of fish you want? Do you want plants or a fish only tank?
also research your fish before you buy them. many pet stores will sell fish that will overgrow the tank they are in, and a cute 1 inch fish could turn into a 8 inch fish.
also read up on cycling. pet stores like to sell "instant cycling" product and in my opinion i would suggest you stay away from these.
i cycle my new tanks by having it run for 3 days, then i get 3-5 ghost shrimp and let them stay in the tank for 4+ days. then i do a water test and go from there. you can use fish for this but i don't recommend it because you could end up loosing them and ghost shrimp are relatively cheap.
http://www.monsterfishkeepers.com/f...nly-filtration-(why-not-popular-in-the-hobby-)
I recommend you use plants. Try making a plant filter, i made mine by sticking an egg crate in my 40 breeder and just rested the peace lily/pothos in the holes. Haven't had any nitrate in my tank since it started working. Makes for a very low maintenance tank, and the fish couldn't be happier
stay on mfk and read read read before you buy anything, this will solve all your worries. if you can name it, someone on mfk has probably experienced it so like they said, do your research before hand and you will have a nice setup. stay away from 10 gallon tanks too, the biggest mistake ive made is getting a 10 gallon and not researching my fish before hand. now i know better so get a 40 breeder or a 55 to start out with and it will make this amazing hobby that much more appealing to you.