I'll second Tam's suggestion on the iStick 50W... it is simple to use and easily "grows with you". Place it in Wattage-mode and you can start low (say 7W?) and keep bumping the Wattage higher until you find the heat and vapor production that works best for your juice and tank combo. Some juice/tank combos will like 10W, some will taste best at 20W, even if it is the same juice, but a different tank or coil resistance.
For a beginner, I would suggest 1.5-1.8 Ohm coil resistances, and if you were a 2-pack-a-day smoker, 12mg nicotine may not be enough for you. As Bebop said, with today's modern tanks, they require more power and put out more vapor (which means the nicotine delivery is more efficient) but you may want to also pick up some 18mg juices (or even higher) because you'll need the additional nicotine during the first few weeks of vaping... to curb the cravings for all the non-nicotine garbage you're missing from the cigarettes. Your body has to detox from over 5000 chemicals in analog smoke, and nicotine is only ONE of those... but higher levels will help you pass the cravings faster.
Another tank to consider is the Kanger Subtank Mini. There is a wide range of coils available for them, and they are IMO a perfect tank for beginner or advanced user. The Triton 2 is a good tank too, but there are fewer options for coil resistance available (nothing in the 0.5-1.6 Ohm range), which is what keeps me from using one as my go-to tank, but my GF uses one daily, as well as her Aspire Nautilus tanks. The 1.8 Ohm coil does provide a lot of vapor and flavor though, so don't think they are bad... I just think they should have more coil options available, lol.