There is a ton of information about knits and different techniques that you can use, I don't want to over load you. But I think starting with some simple projects and building on that base of confidence is the way to go! So I'll briefly explain some different types of knits and their uses:
This is probably the one that you most familiar with. Jersey is soft and light. Most t-shirts are made form Jersey. I would never recommend using Jersey for dresses or skirts because it is so lightweight that it tends to be really clingy and not very flattering. But it's perfect for t-shirts, leggings ( if done right) and airy sweaters.
This knit is made from using two yarns instead of one. This fabric is thicker than Jersey but still nice and comfy. I love double knit! Dresses, skirts, sweaters, I'm getting inspired just thinking about it. This is the knit I would recommend for a beginner.
You'll most tank tops are made from Rib Knit. It's very stretchy and recognizable from the long vertical "ribs" that run lengthwise.
Ponte is very similar to the double knit. It's one of my personal favourites to work with. It's thick enough to use for dresses and skirts but still a little stretchy and really flattering. It's not as stretchy as some of the other knits so be mindful when buying.
Like I said above when starting out I think double knit is the way to go. It's stretchy, comfy, forgiving to sewing mistakes and mishaps (it happens, most likely late at night right before your bobbin thread runs out, frequent sewers know what I'm talking about) and it's really flattering to wear. Ask at your local fabric store and they will be able to point you in the right direction if your not sure what to look for.
Every sewing machine has the capacity to sew knits. Not only are there stretch stitches on every machine but also a few easy techniques that you can learn to make sewing with knits quick and simple every time. The idea behind these stretch stitches is that a regular straight stitch is very stable and secure but if stretched to the degree that most knit fabrics will stretch too it will most likely break the stitches. The stitches shown below are able to stretch with the fabric and therefore not break when strained.
Here are some common stitches that are available on most sewing machines
Great for finishing the edge. Great when paired with the slant zig-zag for a really secure seam. For a more secure stitch I recommend using a narrow zig zag width.
This stitch is really secure and great for seams that have a lot of wear and strain such as waistbands and pockets.
Great for main seams. Quick because it seams and finishes the edges in one go.
Along the same lines at the Over-edge stitch. It seams and finishes the edge in one step.
Most patterns that you buy come with the standard 5/8" or 1/2" Seam Allowance. If you are using the zip-zag, overedge or slant overedge you will need to trim the seam allowance to 1/4". If you chose to use the slant zig-zag than sew at the regular seam allowances as indicated on your pattern and then trim to 1/4" and edge finish with the zig-zag.