Any course you choose should teach the basics of packing light, planning meals, map and compass skills, and leave-no-trace sanitation tactics. For more tips, read Basic Essentials Backpacking, by Harry Roberts (The Globe Pequot Press, 1999; $7.95).
National Outdoor Leadership School (from $2,490 for a two-week trip; 800/710-6657) and Outward Bound West (from $1,295 for a seven-day trip; 800/477-2627) both offer supervised beginner courses that include group gear (tents, cookware) and food.
,a href="http://www.sierraclub.org/outings/national">Sierra Club Outings (from $445 for seven days; 415/977-5522) has volunteer-led trips to the Sierra Nevada and the Wind River Range. Food and cooking equipment (but no personal gear) are provided.
Sierra Wilderness Seminars ($450 for a three-day trip; 888/797-6867), the company that conducts REI Backpacking 101, offers guided treks to the Sierra Nevada that include group gear, food, and two in-store, pretrip clinics.
Other options. College-affiliated outfitters offer beginner backpacking trips for the public as well as students. Though guides' experience level tends to be lower, trips organized through college groups are typically shorter (three days versus seven) and cost less.