First of all I'd suggest taking a class in any art field, it's really worth it. I'm not exclusively talk about college level, even night classes will do. I did that, and it really helped me to left behind some of the struggles I had when I tried to learn it alone. There are many great self-taught artist though so it's not impossible(In fact, my favourite artists are self-taught); but the expert opinion of the teachers obviously are much more valuable than the posts of your friends on deviantart. See it as an opportunity to meet with real artists, there is also a chance that you find out what you really want to do with art. I'll be a printmaker in may hopefully, but I also had anatomy and painting classes as well. I do better and better paintings and this helped me to realise that I have talent and passion in this field, something I could never imagine like 2 years ago.
In short, if you have the chance, take a class or find someone who could teach you. If not, get shitloads of books or a library membership. You should learn a little geometry about the basic forms and the perspective, then you could move on to anatomy(for starters draw leaves and vegetables, bones and other organic stuff). If you have some free time I'd also suggest to learn about the history of art, especially about gothic, renaissance, mannerism, baroque, impressionism and expressionism. Here is a site for that to get the big picture
, but wikipedia is also great on the subject.
Just google "color theory" if you want to know more about colors.
Get a collection book of an artist's works to examine their technique, I highly recommend the drawings of Leonardo, Rubens or the prints of Rembrant. Find someone you like and try to copy them, it really helps to develop your skills.
On the subject of basic drawing and anatomy, the books of Andrew Loomis or Burne Hogarth are pretty good.Try PDF if you are short on money/lazy. THis one is also a great book, and very expensive too.
Also, practice a lot. Draw your dog, cat, family members, room, the neighborhood, yourself from a mirror, your hand, your feet, everything. All you need is a notebook, some 2b pencils and a lot of commitment.
I'm sorry if I misunderstood you and you don't want to know THIS MUCH, but you said you want to be good at this. I wish I could point you in the direction of HOW TO BE GOOD AT ART tutorials but it's not that easy. You have to decide how much time you want to put into this. There are good tutorials though but if you depend too much on these and you don't put effort into mastering your skills you always will be a dilettant "artist" like these kids with their twillight fanarts and anime shit.
Hope this helps, If you have specific questions maybe I could help you out more. Good luck.