Here is a list of some frequently used knitting terms, both here and in the knitting world at large.

knit stitch: One of the two basic knitting stitches. This stitch makes a "v" shape.
purl stitch: The other basic knitting stitch. It forms a "bump."
garter stitch: Another stitch pattern, when knitting flat, this is created by knitting every row. (Or purling every row, but it's not something you see very often.)
stockinette (or stocking) stitch: This isn't so much a stitch as it is a stitch pattern. When knitting flat, it's formed by knitting one row and purling the next. Stockinette is the most popular stitch pattern there is; it's what everyone thinks of when they think of knitting and knitted fabric.
cast on: Knitting has to start somewhere. This will get the yarn on your needles and ready to be knit.
bind (or cast) off: This is how you get the loops off your needles and secure them so you can finish off your work.
working yarn: This is the yarn that goes from your ball of yarn to what's on your knitting needles. It's your "active" yarn, what you use to actually knit with.

English knitting: Also called right-handed knitting (though it's not required to be right-handed to use this, nor that right-handed people have to knit this way), this is the method of knitting in which you hold the working yarn in your right hand. To make a stitch, you wrap the working yarn around the needle; this is also called "throwing" the yarn.
Continental knitting: Also called left-handed knitting (left-handedness not a requirement), this is a method of knitting in which you hold the working yarn in your left hand. To make a stitch, you use the tip of your needle to grab the yarn and pull it through the loop, also called "picking."

dye lot: Natural fiber yarns are dyed in batches. No matter how careful the dyer or the company is, different batches of the same color come out looking slightly different. So, to make your knitting life easier, yarn companies number their batches — called dye lots — and label the balls of yarns with their lot numbers so you can easily find truly matching yarn. This is why, if you're working on a multiple-ball project, you should be sure to buy enough yarn at the start. Many acrylic yarns are produced with no dye lot because the manufacturing process is different. Keep in mind that dye lots shouldn't be an issue for us in this class, but it can be important in your future knitting life.
frog: Sometimes, you just have to tear out your stitches and start over. It's a fact of knitting and nothing to be ashamed of. You can say you've had to rip out your project, or unravel it, but where's the fun in that? In some circles, the acting of unraveling your project is called frogging, as in, "Dag nabbit, I have to frog this hat. Again." But why frog? Because you've got to rip it. Rip it good. Rip it. Which sounds a lot like ribbit, the sound frogs make. Yeah, it's a horrible pun, but what can you do?
LYS: This acronym stands for local yarn shop/store, specifically in reference to those specialty shops dedicated to the yarn arts. Typically, you'll find more luxury and natural fiber yarns here than acrylic or budget yarns. Folks at your LYS are probably very knowledgeable and helpful, should you need advice or more personal explanations. And, you'll usually find regular knitting groups hosted here, if you get really into it.
gauge: Gauge, in a broad sense, is to knitting what thread count is to fabric. Gauge tells you how many stitches and rows you have in an inch. This information is key when you're working on larger or more complicated projects, particularly garments. For the purposes of this class, gauge isn't too important, but you'll want to have something in the vicinity of the gauge listed on your yarn. (This should be somewhere in the vicinity of 4-5 stitches an inch using US size 7-9 needles.)