The best way to get a meal at an Indian restaurant is to go with a group of friends. Order an entrée for each person and then share everything. Be sure to order some raita (yogurt -- it adds flavor to most dishes and can help cut the heat) and a couple of orders of naan (flatbread) to accompany your entrées. Mix your order between vegetable and meat dishes, but make sure you know how adventurous you feel. If you've never eaten at an Indian restaurant before and you aren't usually the type to try new, "exotic" foods, order this for a group of four: fish tikka masala, chicken Madras (sometimes this will be called chicken curry -- it's a mild curry), palak paneer and channa masala. For more adventurous eaters: chicken vindaloo and rogan josh (lamb), accompanied by aloo gobi and palak paneer.
I usually spread basmati rice over my plate (it will be served with your order), then heap the different dishes on top. You can nibble on the naan between forkfuls or, if you aren't worried about appearing uncouth, use it as an edible spoon.