Trusting the tattooist isn't hard if you've done your research. Look the guy/girl up, check out their work, go into the store and talk to them. Get to know them a bit, basically; if they seem like they know what they're doing and you like their work, you'll probably be okay.
The tattooing itself isn't so bad in retrospect, though at the time it's a bit "why yes, that is a needle in my fucking skin D:". The line-art's not so bad, but shading/colouring will hurt a bit.
Make sure you've eaten before you get the tattoo done, and be sure to have something with a fair bit of sugar in it. It helps.
And avoid like the fucking plague any tattoo studio that seems dodgy, or any tattooist who rubs you the wrong way. It's all too easy to get a bad piece of work on you, and a bitch to get it removed.