Before you sew a pattern, make a muslin (a practice garment) first. You'll spend fewer hours making garments that don't fit or flatter you, and you'll become a better seamstress as you practice constructing your pattern.
Sometimes you run into a sewing challenge that no amount of Google searching can solve. For me, it's often a question about fit – an issue that I'm seeing with my pattern that is unique to my body. Luckily, the sewing community is so large that you never need to go it alone. Turn to one or several of these resources for help the next time that you get stuck.
No matter how many knits I sew, I always have this checklist open as a reference. Use this as a reminder of key steps as you're sewing your knit patterns.
Knit fabrics have an undeserved reputation for being difficult to sew. They're actually easier to work with than wovens and are more comfortable to wear.
Sewing doesn't require a lot of equipment, but there are some essentials. Learn which supplies you should buy first, including what to look for in your first sewing machine.