[PaintLily]

I may have used this as a way to improve myself... And I've gotta say I'm quite happy with the results, although I think I made the top of his head a little too long.

Anyway, I would definitely suggest looking at lots of pictures of whatever you are planning on drawing before your draw it; basically, study the anatomy of the animal you intend to draw, not one specific picture (same goes for humans). If you want to draw a dog or wolf--or any animal with different breeds/species--look up the particular breed you wish to draw (That's advice for myself too XD). I draw wolves most of the time, so that's what I have drawn above.
Drawing sketches before I drew the final product used to make my drawings worse, but now it helps a lot. I'm not exactly sure what changed, but I'd say just see which way gets you a better result and go with that. If drawing without a sketch turns out better for you, I would still recommend trying drawing a sketch first every now and again, because as you progress in your art, sketches could prove to become useful to you. If you do draw sketches beforehand, don't be afraid to make small changes in the finished lineart; as you can see in my drawing above, I made the ears a bit smaller and less pointy and the muzzle just a tiny bit shorter than in the sketch I did. Also, if your drawing on the computer, do your sketch and your lineart on seperate layers, it makes it a lot easier.
And of course, one of the most important things: Practice, practice, practice! And no matter how much it feels like you'll never improve, or how bad you feel about you're art, keep going! You will get better, no matter how much it feels like you won't. Beating yourself up and thinking negatively about your art only hurts you and your art (if you say you can't do something, then you aren't going to be able to, but if you think positively, you'll do a lot better.), so don't do that. That's speaking from personal experience, and who knows, maybe you don't ever feel like that, and if so, that's great! But I know I have felt horrible about my art and thought I would never get better, and it's not fun, nor is it easy to stop that thought process, but it's really best to nip that in the bud.

Also, as far as referencing goes, I would suggest that you read this forum post about it, it's quite helpful: How to use a reference CORRECTLY
Unfortunately, the very helpful diagriam that used to be displayed no longer shows up due to photobucket's changing, but it is still a good thing to read.