Thus, sag paneer is cheese cubes in spinach sauce. Very tasty. (Happens to be my favorite dish.)
Naan is a flatbread. Also very tasty. Unless you're with someone with a gluten allergy, you're unlikely to go wrong ordering a plate of naan to start.
As with Chinese restaurants, sharing of entrees is generally encouraged. Also as in Chinese restaurants, many Indian joints have stellar buffets.
Also, lots of Indian places offer combo dinners for 2-4 people, where they've done all the decidin' for you already. That may be the way to go if none of you are familiar with the cuisine.
Hope this helps, and that all y'all have a great meal!