Not sure if the is a species question or a 'I have never received fish in the mail' question. Can't help with the species, but if it is 'I have never gotten fish through the mail'.
1) Float the bags for 20-30 minutes.
2) Empty the bags of fish through a net into a seperate pot/bucket.
3) Only put the fish into the tank. NOT the bag water - amonia and drugs!!!
4) rearrange rocks if you like - depends on what is in the tank I guess.
5) Turn out the lights / you can even put a blanket over the tank to keep things calm if need be, again would depend on what is in the tank already, and don't worry about feeding them until the next day. Let them recover a little and get any drugs out of their system.
There is a section on mailing and recieving fish in the library section, I think. Check it out. If I remember correctly, the article recommends the drip method of acclimatisation. Then I also hear that the drip method is no good because it causes an ammonia spike or ph crash (sorry I forgot which). For me, I just equilibrated the temperature and netted the fish directly into the Q tank. No much problems so far.
Yes, rearranging the rocks and covering the tank are good when they move from the quarantine tank to the main tank. But it is ideal when acquiring fish to quarantine them first so you don't introduce disease to your main, healthy tank.
I float and net. I think the key is to be there when they are delivered...I try to work from home that day so I can get them right into the tank as soon as they arrive.
I would highly recommend you always quarintine your new fish for three weeks, especialy those bought online. you can't possibly trust 100% what the fishes previous living conditions were. I wouldn't even dare chance risking my other fish to infection/parisites from new fish. I speak from experience. One time I bought some fish online from a highly respected dealer that advertises on this site. Well, I put them strait into the tank, and two weeks later I lost ALL of my fish except for 2 synodontis Multis. and one Aulonocara Jacobfrebergi "Otter Point". I was Totaly bummed. I still buy online at times, but I will never make tha mistake of not quarintining again.