Don't get overwhelmed. Here's my first experience:
About 3 years ago, I had started noticing "water vapor" cigarettes advertised on TV. after enough curiosity, i went online and did a little bit of poking. The first link I clicked on was the Blu CIgarette website. Merrily, I got excited that it was so much cheaper than the ones advertised on the TV. Silly me. I dove headlong in without a second thought and dropped a cool 60 bucks altogether for a kit with a personal charging pack (PCC). At first, it was really cool. then, week three came along...
i was already receiving wicking problems with the filler in my cartridge. a month in, an atomizer burned out. three months in, I dropped a battery and it came apart. To top it off, I discovered that Blu has awful costumer service. I had already recommended them to friends, and a couple bought them. This was when I started looking deeper into the internet than google's page 1.
I found a cheap vendor online through amazon and bought some 510 batteries thinking they were "generic blu cigs" (LOL what a NOOB!). When they arrived, i was more than slightly confused, but noticed the threads fit my atomizer. so I screwed it in and merrily resumed vaping, for the moment.
being used to Ni-Cad batteries, i drained each battery before recharging them, recharging them in my blu usb recharger after. OOPS! It just so happens that Blu Cigs wires their + and - directly opposite of the industry standard. each of three brand spanking new batteries, fried. Of course, I had no idea this was the case and lamented to the skies, wailing in ash with the gnashing of teeth.
Then, as time went on, I got a little more versed, a little more experienced - found more reliable information, started using egos, tried tanks, tried an assortment of cartos, tried passthroughs. Now, i'm in search of the indestructable, so I'm starting to branch out into mods and rebuildable atomizers. There's definitely a learning curve to this whole experience, and you can settle wherever you feel most comfortable. And if you get bored with that, there's gonna be something new to try down the road. (I'm still very curious about what I read was the "original design" for the nicotine-delivery system using ultrasound...)
As for liquids, it's almost entirely preference there; someone complains that a particular flavor tastes too much like the candy-version of the flavor, but someone else LOVES the candy banana flavor (I've recently been enjoying Cinnibiscus from Madvapes.com, which really tastes like a hot cinnibon). Someone swears by PG juice, but others have an intolerance to it, or just prefer Vegetable glycerine (I like tank systems, so I usually use a mix of PG and VG). I've bought from people because they were highly recommended, and been unimpressed. I've bought some stuff simply because it was cheaper and been pleasantly surprised.