I would definitely read through this sticky on the subject.
When to go from Primary to Secondary (If at all
It will answer most of your questions and you will learn a lot more than you wanted to.
There are a lot of opinions about how to take a sample, but my method is using a sanitized turkey baster. I squeeze the bulb, put the very tip in the beer, and suck a sample up. The key is to squeeze the bulb before you put it in so you don't introduce any oxygen into the beer.
Hope this helps and good luck!