As far as good residents it is a matter of preference. All are good, if you know how to care for them and none are good if you do not research and take your time with set-up/cycle and then more research. It would be almost impossible to give you all the info you need in one thread, at least within a few pages.
As stated above, get some books on S/W keeping and/or search the web. There is a ton of good info available.
Just a basic rundown, first you need a tank, then a heater, maybe a chiller if it gets above 80F in the room you are going to keep the tank in, then some good water movement pumps, probably a sump/refugium, protien skimmer, proper lighting if planning on keeping photosynthetic creatures, salt mix, RO/DI filter or a good source for RO/DI water, and I am sure I have left out a few other peices of equipment such as refractometer, thermometer, ph test kit or monitor and basic test kits for nitrate, phosphate, etc.
That is just the beginnings. Take it slow and research. Money is tight now-a-days and no sense in jumping right into it and flushing money down the drain only to learn from the death of the charges you decide to keep and/or the improper equipment.
There is no rush, reefkeeping and the animals it has to offer is not going anywhere anytime soon.
The time you take to properly research will reward you with a beautiful and enjoyable aquarium instead of a nightmare that has you running out and buying all the latest insta cures and pulling your hair out only to end up selling the tank off within the first 6 months.