First, welcome to MFT and the salty side of life:
In order and importance
1. set up the tank in your permanent location. Add your substrate and don't worry about paying extra for live sand as it will all be live soon regardless. Live sand is just sand that has bacteria already in it and most you see in the lfs is not worth the extra money. Find a local reefer and beg a few cups of sand from them and add this to your sand after every thing is set up and running.
2. Mix your water and salt in a large garbage can such as a rubbermaid brute etc. and mix to an sg of 1.023 to 1.025, fill with good ro/di water not tap water, if you do not have access to an ro/di system you can buy water in jugs at the grocery or from Culligans etc. Tap water often has high phosphates that can lead to algae blooms later on down the road. Once this water has mixed for a few hours you can transfer this to the main display. To reduce the dust storm place a kitchen dinner plate on the sand and pour the water in slowly it will be very very cloudy for a few days but believe me it will settle down after a week. You want that dust in there as it gives more areas for bacteria to populate
3. Add your live rock at the rate of approx 1-2lbs per gallon. Try and get cured live rock but if you can't you can cure the rock in the main display.
4. add your powerheads for water movement to turn over about 20x volume per hour. Add your heater and set the temp to about 76-78 degrees.
5. The live rock should jump start your cycle, monitor for ammonia, nitrite then nitrates....you will need something to supply an ammonia source and the die off the rock should do this. If you use fully cured live rock you may only get a small short cycle. The live rock bacteria will also help settle your sand as the particles become populated with beneficial bacteria and this will weight them down and help them settle quicker.
6. After all your parameters measure zero for ammonia, nitrite etc you will be able to add a clean up crew which will help maintain the sand bed and rocks, eat detritus and basically help maintain your tank. You cuc should consist of a variety of snails such as nassarius, ceriths, astreas, nerite, turbos etc. a good mix of these is good to have as each type has it's own area of specialty.
7. You could add a protein skimmer, it is not essential in at tank that size if you are totally committed to doing water changes weekly as a fish only tank can handle higher nitrates than a reef would. I agree with Jim though if you are going to spend money on a skimmer get the absolute best you can afford as this is something that you will want when you upgrade and believe me you will be wanting to upgrade in the future once the bug bites.
Good luck and keep us posted on your progress......