Advice on taking better quality photos?

Learn photography, practice a lot, and learn to take criticism. Let's start with your link. It's bad.

You haven't made any obvious beginner mistakes. It looks like you could punch up the contrast a bit. Framing is good: it's obvious what the subject is. One improvement that I can offer is not related to technique. You have a lot of head shots of turtles. You're going to lose viewers showing them an endless series of such photos. Experienced photographers pick their best shot and keep the total number down.