Many community groups participate in routine hikes in the Great Smoky Mountains National Park. Here are a few resources I use when I'm looking for a good trail, some places to stop along the way, or some great advice from hikers who have already hit the trail:
Get on the Trail with Friends & Missy - (Wednesdays in April & October), For information: www.FriendsOfTheSmokies.org or registration: 865-541-4500
Great Smoky Mountain National Park - www.nps.gov/grsm: 865-436-1200
Visitor Centers at Sugarlands (865-436-1291), Oconoluftee(828-497-1904), and Cades Cove (865-448-4123), for park trail map and other hiking information.
Smokies Hiking Blog - http://gosmokies.knoxnews.com/ 
Great Smoky Mountain Association - www.smokiesinformation.org or 865-436-7318
Smoky Mountain Hiking Club - www.smhclub.org
Foothill Striders - www.foothillstriders.org
Hiking contact: Rob Carroll, rob@mosesgamblehouse.com; 865-977-8940
Happy Hikers – John T. O’Connor Sr. Center, Knoxville, TN
Belford Mills @ 577-7222 or Lloyd Strange @ 865-525-0767
Thursday Hikers - Bill Little @ 865-681-0095 or Jim Burbank @ jeburbank@charter.net (Jim also leads full moon hikes in Cades Cove)
Wednesday Hikers - Bill Broom @ 865-588-5685 or sweeper7@msn.com
Wednesday Hikers – “friends of Margaret Stevenson”
Debbie Wade @ (H)865-981-9378, (c)865-803-1757 or dbwade@bellsouth.net
Knoxville Track Club - www.ktc.org or 865-687-8493; walking/running club, sometimes plan hikes
Retired Citizens of the Smokies, Gatlinburg, TN - (Fridays and 2nd Tuesday each month) Ray Sellers, 865-453-6462 or Frank Carter, 865-436-3010
Sierra Club – Harvey Broome Group, Knoxville, TN - www.tennessee.sierraclub.org/broome.
UT Smoky Mountain Field School - www.outreach.utk.edu/smoky
or 865-974-3181
Great Smoky Mountains Institute at Tremont – www.gsmit.org or 865-448-6709
Tennessee Trails Association - www.tennesseetrails.org or 866-TN-HIKES (866-864-4537), East TN Chapter – easttennessee@tennesseetrails.org
Fontana Hiking Club, Fontana, NC – Jerry Span, jerry.span@fontanavillage.com, 828-498-2122
Carolina Mountain Club – based in Asheville, NC; http://www.carolinamtnclub.com/
Haywood County, NC Hikers – contact Kathy Ovody at koodvody@yahoo.com; http://groups.yahoo.com/group/Haywood_Hikers_of_WNC/
Nantahala Hiking Club – www.nantahalahikingclub.org
High Country Hikers, Hendersonville, NC – 828-891-6294