Little Ridge Park
Due to my work schedule for most of 2017, I had free time in the mornings. It was great and it gave me the chance to exercise more often. So basically anytime the weather was nice, I went to the park. We are fortunate to live near a very nice park on Lake Lanier, which also happens to be free AND dog friendly! I spend so much time at Little Ridge Park, you would think I lived there. It's not huge but there is a nice trail through the woods and it is easy to access the lake from different parts of the trail. There's also a boat launch but that is about it (no bathrooms or pavilions or such). It's crowded on weekends and holidays but during the week, I only ever see about 2-3 people on the trail. Again, it's dog friendly!! There are a lot of parks on the lake that are not dog friendly. My favorite feature is this island that sometimes becomes a peninsula depending on how high the water level is. You can walk/wade out there and it's just fun to explore. It's very shaded and a good place to put a hammock. Little Ridge is an Army Corps of Engineers park so please review their rules before visiting!!
Bowmans Landing
My other standby has been Bowmans Island, which is part of the Chattahoochee National Recreation Area. It is attached to the Lower/Upper Pool Parks at Buford Dam, which is part of the Army Corps of Engineers. Different rules for each! Leashed dogs are allowed at Bowman's Island but not at the Lower or Upper Pool Parks. They all share an entrance at the Lower Pool Park and if there is an attendant at the gate, they will not let you bring dogs in. There is also an entrance at the Island Ford Unit and I am assuming you can bring dogs in this way, but I have never been to that location. Sometimes the gate is unattended and you simply put money in the box and get your parking permit and you and your dog can be on your way. Bowmans Island is also horse friendly but I have never seen anyone on horseback there.
I love the Chattahoochee and Bowmans Island is an easy way to access it. That being said, this is not a swimming hole/day drinking locale. There are always people fishing and I try to not disturb them. There is a fairly extensive trail around the island and some of it goes along the river and some up into the woods. There are maps all along the trail and I just sort of meander each time I go there. I love seeing the changes in the river due to dam releases or rainfall. It looks different each time I visit. I took these pictures in early fall when the weather was still warm and the river looked particularly beautiful.
So even if you think you don't have time for a hike, you can usually find a "in town" option near Lake Lanier and the Chattahoochee.
Since have longer daylight hours, I'm trying to take advantage of doing some shorter, local hikes during the week (because weekend rain seems to be an ongoing phenomenon in North Georgia). On days I work from home, I can get out the door by 5 pm and still have nearly 3 hours of daylight. Recently, I decided to revisit a trail I'd been to once before, the Laurel Ridge trail along Lake Lanier and the Chattahoochee. James and I did this trail back in 2016 on a hot summer day after my car got totaled and I needed something to take my mind off of it (just one of the many things in 2016 that led to a sad, post-less year). I didn't remember much from that visit, other than it was extremely hot and Lake Lanier had very low water levels then. It's pretty much in the same area as all the other trails I do near Lake Lanier, so I'm not sure why I've not been back more often. 
The Laurel Ridge trail is a 3.8 mile loop with several different options for beginning and ending. I recommend starting at the Lower Overlook park, because it has free parking, and from there, take the trail southeast. There are other options, such as starting at Buford Dam but then you have to pay for parking at the Chattahoochee National Recreation Area. If you follow the trail southeast, you'll go through some scenic low-lying swampy areas with boardwalks and then follow the trail along the lake for a while. Eventually you cross Buford Dam Road (always a death trap) and go into the woods closer to the Chattahoochee. The scenery changes nicely throughout the hike. The trail goes through a few different parks and sometimes crosses a parking lot, so you just have to pay attention to the trail markers. Once you get to the river, you can take the boardwalk on the left hand side to the dam and explore there or continue to the right up the Laurel Ridge trail. Keep an eye out for the goats on the dam! After leaving the river area, you'll cross Buford Dam Road again and be back in the Lower Overlook parking lot, finishing the hike. 
Most of the hike is relatively flat with a few hilly areas as you transition closer to the river. The scenery does change quite a bit throughout and I saw different wildflowers in different areas. I've also seen deer each time I've been here which is always a cute surprise. Since the hike isn't very long or strenuous, it makes an ideal hike or run if you only have a few hours. It took me 2 hours on the nose, with frequent stopping for pictures and exploration by the river. Despite being in town and just off the main road, I only saw a few other hikers (and it was the week of spring break to boot). One downside, since the trail is along a busy area, you can often hear traffic. That aside, the Laurel Ridge trail is a great suburban hike and I will definitely add it to my rotation of week day hikes. 
