I just started a 55 gallon 2 months ago.. here are a few tips:
Look up FISHLESS CYCLING... i did not do this but it is something you might want to try. it involves using pure ammonia to cycle your tank instead of "starter fish"
If you choose not to do the fishless cycling you will need a couple of hardy fish to get you tank started. basically they start producing waste... Ammonia... and then bacteria start growing that turn the ammonia into nitrites and then more bacteria will grow to turn the nitrites into nitrates. I used 5 zebra Danios to cycle my tank. Don't be alarmed when you wake up one day and your tank is all cloudy. that's just the bacterial bloom and should clear up within a week. I have heard that its not a good idea to add any chemicals to make the water clear.. mine is crystal clear now.
You need some sort of filter (i have an aquaclear power filter that filters 300
GPH that i love and
IMO is the easiest because you can change out the filter media at different times) Basically, there are three types of filtration: Chemical (carbon), Mechanical (pulling the water through something like a sponge) and Biologica (your bacteria). If you use a power filter, they have different media in them. like sponges, carbon cartrigas, and mine has some organic stuff that floats on top for the bacteria to grow in. You don't want to change any of this whil your tank is cycling. I don't like UG filters.. and most people that i know don't really reccomend them anymore.
here is what's going to happen with your cycle... you need to get a TEST KIT of course. and test your Ammonia and nitrites every other day ( i actually tested mine daily because im obsessive compulsive like that.. lol) First thing your going to see is the ammonia levels start climbing, don't worry, this is supposed to happen. they are going to skyrocket to the highest level your kit can test for.. after a certain period of time (sometimes 1-2 weeks) the ammonial levels will start to drop and the NitrITE levels will start to go up. These will also peak and then begin to fall rapidly. Mine took a month , but after a period of time your Nitrites and Ammonia should read ZERO. This means your cycle is complete. You can then start adding new fish.. do this SLOWLY, only one or two per week
IMO. This is the stage I am currently at.
Now you need to start doing regular water changes.
IMO weekely 10-20% water changes are the best. I use a gravel vac and just hover it over the substrate because i have live plants. but if you have an UG filter you need to REALLY clean the gravel by agitating it in the gravel vac because junk gets sucked down into it (see why i hate the UG filters) Some people say monthly 30% water changes will suffice. The reason for doing the water changes is to keep your NitrATE levels low (below 20 i believe)
I hope my info helps... I am a newbie as well, but i have done a TON of research and i believe all my info is accurate. GOOD LUCK
