Marietta is not the greatest beer place, but as far as bottle shops, checkout Bullocks on sandy plains rd, or sprayberry bottle shop also on sandy plains rd. For beer places near Marietta, Red Hare Brewing (full size production brewery), Johnny McCrackens pub at the Marietta square, The Wing cafe on Roswell rd, or if you want to take a little drive over to sandy springs 5 seasons brewing (great place ) on roswell rd in "the prado" shopping center, and then there's always any Taco Mac ( sports bar with huge beer selection where the 1st 3 beers you order will not be available) there are all over the metro atl. Oh almost forgot about Trackside grill in Kennesaw nice little place with great outdoor seating who always has burnt hickory beer on tap. Burnt hickory is the holy grail of beer around ATL lately and their production brewery is in kennesaw. They usually have tours / tastings on Saturdays. Check their website / facebook for updates. BTW kennesaw next town over from marietta.
Now if you want to get to Atlanta, just go to Decatur or the little 5 points area for some great beer places, but that's a whole 'nuther list. cheers