I did a lot of research first personally as well as joined the forums. I am new myself, but I started with live rock and live sand.
If I could make one recommendation that will mark your life a lot easier. Get yourself set up with a Brute trash can on wheels, a thermometer for the amount of gallons your trash can is, and a power head for it. Also get yourself and RO/DI filter, and a pump for the trash can to move the water from the bin to your tank. Use the trash can to mix and heat your salt water for water changes.
But live rock and live sand are the best to at least begin establishing your beneficial bacteria.
Get the saltwater master get kit and a syringe to measure out the beakers accurately.
Set up the tank with your hang on back system or sump system. Do you know which way you'll be setting up?
I also wouldn't run your protein skimmer yet. Just do the water changes at first.
I personally have been doing 10% bi-weekly. Cleaning my filter weekly.
Once you're set up, leave it. Don't add anything.
Personally, I kept a very close eye on my initial cycle and literally tested the water every two or three days. It uses a lot of your testing material, but it's also really fun t watch the first cycle happening.
I actually enjoyed it. The time flew. The best piece of advise I can give here is take it day by day. Don't focus on how long it could take, just enjoy what's happening as its happening.
While your tank is doing the first cycle, explore local stores that you may have that specialize in saltwater fish. I am lucky to have two stores. One of the stores was even featured in a magazine that talks about saltwater fish. He's apparently a well known guy in the hobby. I'll have to find the article to share.
Steer clear of certain LFS though. I always make sure that they are clean, the fish look healthy, I find out where they get the fish and how those fish were raised; wild caught or tank raised. I like to get my fish locally instead of online, my experiences just haven't been good.
When you start with a fish, my personal recommendation would be to start with a clown fish. I tried Blue Green Chromis, but took them back after everything became established. They were eating all the food before other fish could get to it, and damsels, though hardy, are territorial fish.
If it were me starting again, I would make sure my tank was cycled, and my first addition would be two clowns. I know most people say to only start with one, but clowns should be added together, or if you add one later, you need to make sure it's much smaller because they can fight.
I also bought 'Nutrafin Cycle' and I used that as instructed on back, and each time I've added a fish I do 10ml per 10gal.
So this is just me starting up. I'm lucky to have some friends that I work with that know saltwater tanks, and people here are so eager to welcome new hobbyists and all questions. They give great advice and are always very friendly.
So I hope this helps, I know that everyone has slightly different advice on starting, but you'll see it's also all very similar.
Keep in mind, with a 55 gal(I have a 60), we can't add really large fish. The biggest I have is a dwarf angel. It's a Coral Beauty and seems do be doing great! Our max amount of fish would be like 5-8 small ones.
All in all, for example, I have: Diamond Goby(so much fun to watch), 2 clowns(ocellaris and snowflake), coral Beauty, a wrasse(can't remember the exact kind. Black with a blue strip down the middle on both sides), 2 snails, cleaner shrimp, an anemone, small leather coral, small polyp(I think?)
So that's all I'm adding to my tank until I decide it's time to upgrade.
I think most people get bit badly by the saltwater hobby bug lol.
It's so much fun! I think the beginning is awesome. You're constantly doing so so much and learning new things literally every day!
Keep us updated and good luck!