While Knitting

Now that you're knitting, you have a few different things you'll need to keep track of! 

First, make sure you have a copy of your pattern handy if working from one of those. Some folks prefer a printed copy, others like to mark up a PDF, still others just look at it. 

Notions

You'll almost certainly need to keep track of your rows and potentially your stitch counts. Row counters and stitch markers are your friend. 

For keeping your stitches on your needles (important with especially hefty projects and short needles, but also just useful if you ever take your knitting anywhere!) make sure you have some needle tips / point protectors / whatever else they might be called. These are typically little rubbery things to put on the ends of your needles so that the stitches can't go past them and fling themselves off into the Unraveling Lands.

Needles

What kind of needle you use is also an important piece of the puzzle. While it's best practice to avoid switching needles in the middle of a project, sometimes needles break or you just hate using them for this project. You might start with double pointed needles (DPNs) and then switch to circulars, or vice versa. I also strongly prefer to use circular needles, even on projects worked flat where straight needles would suffice - because then I'm not fighting with the tail end of the needle for my grip and find my tension is looser and more consistent this way.

The material your needles are made from could also be a point of interest. Some folks strongly prefer the slip of a metal needle (steel or aluminum are the typical offerings) while others find their tension benefits from the slight grip that bamboo or wood can give them. Sharpness of point will impact how easily your needle can go through the stitch, but sharp tips may also make it more likely that you will split the yarn of that stitch (undesirable). 

This is all, unfortunately, largely a matter of personal preference that requires extensive trial and error to find out what you actually like. This is why craft supply swaps are a huge boon - you can probably find needles for free at a craft swap to find out some of these basics!