Well, the best information you can get in on this forum:
e-cigarette-forum.com The place for electronic cigarette reviews, news and chat
There are many different kinds of ecigs out there. But they mainly consist of a battery, an atomizer and a cartridge. The battery sends electrical current to the atomizer that has an internal coil that is soaked in e-fluid, causing it to atomize due to the vibrations in the coil. The atomized fluid is then inhaled into the lungs and a vapor comes out upon exhalation.
The first one I tried was the DSE-901:
Now, I'm using, "The Cadillac of ecigs:"
The Screwdriver
If I were to take a blind test, I wouldn't be able to tell the difference between the two as far as smoking experience.
New Zealand conducted a test of these devices and found them safe for users, and those exposed to the exhaled vapors in a, "Second-hand," environment.
I didn't even expect to quit smoking altogether, either. My tobacco plants didn't want to grow, and I was going to go to ecigs as a backup.
That forum linked above is the place to go for the best as far as prices and reviews on it.