Advice for a new reefer, please :)

[cd77]

After having success with various freshwater tanks, including freshwater plant tanks, and various south american cichlid tanks, I've decided to start a saltwater reef tank and a friend told me that reefcentral was the place for good information -- I've got a few questions if you don't mind my asking. I'd like to get off to a good start with some solid advice

I bought a 70 gallon tank, pre-drilled with a sump/refugium/pump/skimmer and a single powerhead. The tank is stocked with live sand, about 50lbs of live rock, and I plan to add another 40-45 more pounds of rock this Thursday. I plan to cycle the tank with the live rock.

My questions/concerns are the following:

1. The tank seems to be steady at about 80° -- is this OK? Once the tank has cycled (according to the guide I recently read on this site) I plan to add some live corals, and tank "janitors". The reef keeper at the local pet store (I'm in the midwest, so good saltwater shops are few and far between) If 80° is too high, what do you suggest the proper temp be? any suggestions for cooling the tank besides a chiller? I'm running the lights on a 12 hour cycle during daytime, with the refugium lights on 12 hours at night.

2. When I add the new live rock, I plan to re-organize the rock that is already in there. I've read to make sure that the rock does not touch the glass and to minimize dead spots and allow for plenty of circulation. How far from the glass should I keep it? I'd prefer the rock to be towards the back of the tank as I plan to add nice fish later down the line. Any other suggestions on rock placement?

3. I've read that the plastic hydrometer I bought is worthless and that I need a good glass one calibrated for water temp (?) If so, any suggestions on what to get and where to purchase it?

4. How soon before I should think about adding corals? I planned to wait until ph/amon/nitrite/nitrate is stabilized and then add the corals -- or should I wait until everything has settled and watch for a slight spike in nitrate before adding corals?

5. What exactly are "tank janitors"? What species should I get?

6. Any suggestions on what types of corals to start with?

7. Any other starter suggestions? resources? books?

I've added a few pictures at http://www.christopherandlena.com/ga...2_itemId=30854 -- including a picture of the sump, the tank, a close up of a couple rocks, and some sand that has a slight brownish tint to it -- something I need to be worried about?

I know I have a lot of questions here, and maybe most of them are best answered elsewhere -- if there are simply links you could send that would answer these questions, I'd still be much appreciative!