I might be able to help since I just recently started, and went through a ton of info.
Here's my take. At first I got an Joyetech (make) eRoll (make), those are the cig-a-likes, but quickly found the constant filling and heating up annoying.
Then I got a Joyetech (make) eGo-C Twist (model) 900mah (batter size) which lasts me almost a full day going through about 3-5 ml of juice at 12mg nicotine (I smoke about a 1/2 pack to a pack a day for 8 years).
For the Twist, I got a Kanger (make) T3 (model) clearomizer (the type of juice delivery system), for these you buy extra coils specifically for the model to replace every week to 2 or once the flavor turns bad. But then I read some scary .... about the wick (material that the juice soaks in through to the coil that burns it) being from silica (or something like that) and apparently it might be dangerous to inhale. The wicks can be redone/rebuild to use cotton or bamboo but it's too much of a hassle, and requires some other devices.
Then I decided to try cartotanks (cartomizer with a tank, this is the second type of juice delivery system). By that time, my plastic T3 got ugly from constant use, all scratched and beat up. So I decided to go with a pyrex system (some sort of glass?) which holds up better but is still prone to breaking if dropped. There's a couple people who make pyrex cartotanks, but I found IBTanked (maker) to be the best bang for the buck. Some other are little vendors, and Phiniacs (another maker) but those cost much more. Ordered the complete set, some extra cartomizers (which, once again, need to be replaced every few weeks just as the coils in the clearomizers). I got the Smoktech pre-punched 2.0ohms (you usually take the ohm rating, multiply by 2, and that's your maximum voltage - you can go anything below, just try it out with the juice you're smoking, but in this case I set my Twist to about 4 - 4.2). I haven't tried other cartomizers, but Ikenvapes are supposedly good but hard to find. I'll try to get an order of them, along with Boge cartos at different Ohm ratings to taste the difference. Low Resistance (LR) 1.8-2.0 ohms, from what I understand, give a more warm vape, and Standard Resistance (SR) 2.4-2.6 Ohms have a cooler vape. I've been very happy with the IBT tank, and will probably order more because the cartomizers taste weird if you switch the juice you're pouring in at some time. As a recent smoker, I like the crackling popping sound the cartotanks make which I didn't find with the clearomizer.
Now, I'm deciding whether to get another Twist as a back up when the one I have runs out of batteries - which is frustrating (probably the 650mah one since it's smaller) or jump straight to a Provari (the more expensive, but better USA made one) which is Variable Voltage/Wattage and all that jazz. Mechanicals and RBA atomizers are still confusing to me at this point, and I'm not sure I want to go that route.
Feel free to make your decisions based off of my story so far, but do research anything you found confusing in more detail. Also, visit an actual physical store if there are any in your proximity as that cleared up a bunch of questions for me by being able to try, taste, and touch different devices and juice.
Best of hopes,
Aleks
