For the device, one thing to consider is how much you want the device to "look and feel" like a cigarette. The absolute closest you are going to get to the look and feel, without having something that just completely sucks like the mall/gas station brands, is an automatic 510. A manual 510 is better -- you have to push a button, but that makes it easier to control and more reliable -- but still roughly cigarette shape and size. If authenticity is really important to you, you can probably find one in white.
If you think closely replicating the size/shape/appearance of a cigarette is not so important to you as quality, this opens up the option for some better models. An eGo is a good stock model that will be easy for a beginner, or a Riva is even better. You might even consider a basic mod like an e-power.
All of the devices I mention above are very common and sold at a variety of places. If you go the 510 route, you'll need 2 or 3 batteries at least even to start out, because the batteries will only last 2 or 3 hours on one charge. For eGos you still probably want 2 batteries; Riva you could probably get away with just one but you still may want a spare to keep charged. In addition to the batteries (and the juice and cartomizers as I talk about below) you'll want to have at least a charger for your batteries. A lot of places sell starter kits that have 1 or 2 batteries along with a charger and a few other things, which can be easier as a first purchase than just buying everything separately.
For the accessories, I think a pack of cartomizers at 2.0 ohms is probably going to be the easiest and most like a cig for starting out. Later on, you might find you like other things like dripping or different resistances, but cartomizers are lower hassle and 2.0 ohms is going to both work on most devices and provide a decent vapor and throat hit. Personally, I like Boge brand cartomizers, and most big vendors sell those.
For juice flavor, the closest I have tasted to Marlboro lights is the Dekang USA Mix (called Marlb some places). This is a common juice so you can also find this at a lot of different vendors. But I'd also recommend that you order at least a small bottle or two of non-tobacco juice. I quickly found after switching to vaping that cigarette tobacco flavors were just not appealing to me at all, and I preferred using other flavors almost immediately. Having all these choices is one of the great things about vaping. If you're a heavy smoker you might want to start out on the high side for nicotine content, maybe 24mg.
For where to buy all this stuff, a lot of people will give you good reviews of their favorite vendor. I've generally had good experiences with Madvapes.com and also cignot.com. But one thing to at least consider is finding a vendor that's located relatively close to where you are. No matter how good a seller is at getting the product out the door, the USPS can be a limiting factor to how quickly you get stuff, so it's nice to have a vendor close enough so that it only takes the postal service a day or two from pickup to delivery.
Finally, just be aware in advance that nothing is going to look, taste, or feel exactly like your cigarettes, so don't get discouraged that it doesn't. But just keep using it, and I think whatever you get, it won't be too long until you much prefer it to the old cancer sticks.
Good luck and kudos for your service and for your good motivations to quit smoking!
