Asking this question would give you as many different answers as there are people who reply to it, each have thier own opinion.
As a newbie myself (going on 3 weeks this comming monday) I can tell you our (my wife and I) experiences, and hopefully they may help.
I read countless posts here for days, watched video reviews, read all the great stickies in the new members forum which I Strongly reccomend you take the time to do by the way.
A lot of the first impressions you have now will very possibly change after reading up, or actually trying one. On first blush we also thought oh, it needs to be small, look lige a cig, be automatic etc.
On further study, and hearing of issues with the manual batteries being oversensitive etc (some may not be) we decided to opt for a manual battery type.
The manual batteries you need to press a button on, and while compared to smoking an alalog you may find strange, the first day using it here it became the natural way of doing it very easilly withought even thinking about it.
The smaller the battery is on your ecig, the more frequently you will need to change it for a charged battery.
Most people I see (and us) start with a smaller ecig, and a lot end up getitng another (or MANY others) afterwards with a bigger battery.
Most with multiple types use them for different occasions, so it is not a bad thing to end up with a few.
What type you start with should depend on a few key factors:
How tollerant (or not) are you with fiddling with them?
If you are not, then a cartomizer model (2 piece) is probably a safe bet.
If you are, then any would be ok in this regard.
How much do you smoke / what is your daily situation.
The more you smoke now, the more you will likely vape, hence you will go through more battery power / batteries. Do you NEED something small to fit in a pocket etc that can last you all day on the road, outside etc, or are you a home or office type with access to power for recharging or passthrough type devices?
If you need to be self reliant from main power, then either a big battery mod, OR a small ecig with either a handfull of batteries OR a PCC to recharge them on the go is suggested. (you can also get powerpacks like kensington etc but that also takes up more space)
Answering the above shouldl help you narrow your focus as to a model to select.
Most verything else is a matter of taste/opinion, but the more opinions you get on various models the better you will see what each is like before you buy.
Do your reaserch, it should pay off as only you can say what you like, not us.
We started off with the 510, and it is probably the most reccomended starter here, with the 901 being a close second.
Since then we ordered 2 Protoge's so as not to be tied down to batteries so much (the 510 pcc's are less than perfect as you cant put an assembled 510 in it, but it can get the recharging job done)
If you really need/want an analog look with portability and a smart pcc, the new revolver elite that Nikko reviewd here is worth consideration and if I hadn't have gotten the 510 I probably would have went this route for a starter as I was also looking at things like the blu, ss no 7 etc with slick pcc's:
http://www.e-cigarette-forum.com/fo...28-video-review-revolver-elite-e-cig-pcc.html
Good luck!