Good advice above. I have a 12g nanocube and absolutely love it. I cannot stress more the importance of water changes with small systems like this. I do 25% water changes twice a week on mine and have no skimmer, and this keeps ammonia, nitrite and nitrate levels undetectable. I'd recommend between 8-12 lbs of live rock with a two-inch+ aragonite sandbed.
As far as inhabitants go, the goby/pistol shrimp pair will be great. There are plenty of other nice small fish that would be good in your 10g:
Nano Fish
Keep in mind that while your tank may be able to hold 10g of water, it will hold more like 7-8g after all the substrate and live rock are added, so this is a small volume of water. Water and air circulation are important to make sure the temperature doesn't spike. Also, a lot of evaporation occurs in a tank this size, so you'll need to be topping the tank off with freshwater pretty often.
Take it slow with the cycling. Corals do terrible if the tank is not fully cycled before you add them (at least 2 weeks of cycling), so please don't rush (as exciting as it may be) and read as much as you can about nano reef tanks just to get a feel for the hobby. Zoanthids and palythoas are great starter corals as well as are leather corals (I'm actually selling some of mine right now if you check out the Corals for Sale forum). Star polyps and xenia grow like weeds, sometimes too quickly. I'd stay away from SPS corals because they typically require strong lighting (MH) which is very expensive and the bulbs generate TONS of heat.
Please ask lots of questions during this process and don't think that your asking dumb questions. The only dumb thing you can do is to wait too long to ask questions. So ask away!