Welcome to LTG. Kick your shoes off, relax your mind. Since you're the original owner, if you've got the papers, you may want to take it to a Guild Warranty Repair center (if there's one close) to see if it needs a neck reset or any other warranty service (and if it would be covered under the lifetime warranty). If the work is needed, it would delay your ability to sell your guitar which may not be good in your situation, but increase the value of your guitar when you can sell it. If there isn't a warranty/repair center nearby just taking it to a luthier for a once over helps, it may need some minor neck adjustment etc and you can share that information when you list it. Otherwise when folks look at an older guitar they more or less assume X amount of $ to get it set up properly. Sorry you have to part with it, hopefully you'll find it a new good home.
In terms of the best way to sell, if you want a person-to-person sale there Craig's List (count on folks offering less than you ask) or on consignment with a local store. If you don't mind shipping the guitar (plenty of posts here in the archives about how to pack) you could list it here, on acoustic guitar forum, or on ebay. (You'd have to check LTG and AGF regarding posting policies, if you don't have an ebay account some might buyers be hesitant to buy from a new seller.) joan