For bedding, we use a combination of Unbleached White Paper Bedding mixed with Aspen Shavings, Crinkle Paper and timothy hay. We use about a 70-5-15-10 ratio, I suppose. Gerbils love to burrow and build tunnels, so the crinkles, hay, and wood chips help provide structure for their little tunnel networks to not collapse.

If they were scared, they would stay away from you. They're skittish little things, so sudden movements or sounds will make them jump and/or scurry away into their hidey-holes, even when they've warmed up to you. We've been feeding them with an outstretched open palm so they come right onto our hand to feed, then we sprinkle the rest so they can forage later. This helps build trust.

[Edit:] I didn't see a mention of this, but they need a sand bath, as well. We use ReptiSand in a NiteAngel Sand bath box but we have a 40 gallon aquarium, so it's probably too big for your 10G topper. Petsmart or Petco should have something like a ceramic critter bath The NiteAngel fan-shaped sand bath box would also probably fit.