Pros
You can take it as an entry level job at $9 to $10 for a max of 30 hours (most districts) and learn a lot about day to day business. You may get stuck with a boss who doesn't want to delegate responsibilities or teach you things. If this is the case speak up and demand to learn more. Don't just be a part-timer picking orders and putting stock away. Learn something so you can move forward in this company or another one. Branches are like small teams, depending on how you get along with people and how your GM is it can be great or it can be horrible. Corporate says full-time is 50 hours, but working with a reasonable GM you can get out in 40 under the radar.
Cons
The part-timers get stuck doing all the grunt work, which can be really boring at some branches (ie putting patch on 500 screws or more everyday). The full-time jobs have low salaries compared to the industry average and you are expected to work 50 hours for it. The GM and DM are also struggling to keep costs low and keep their paychecks high so there is a lot of skimping at a branch level and sharking for low pay and high hours in this company. As outside sales or higher you'll always get reemed out in emails to do better and better and its never good enough. Its kind of a roll of the dice, but you can end up as OS or GM at a high sales branch or a low sales one. It depends on what opens and how fast you want to move up. My advice is don't get stuck in a low sales branch, you're expected to grow the business and if you cannot you will make little to no commission. With high corporate restrictions on pricing its pretty impossible to grow the business without slowly weeding your way in for years and years. Go somewhere that is somewhat established, but not saturated. You need room to grow.