My answers may not be what you're looking for but I'll take a risk. It sounds to me as if you'd like to do *realistic* drawings -- at least, drawings that might be accepted in mainstream Western society as realistic.
Dog Drawing
http://z.about.com/d/drawsketch/1/0/h/9/...rawing.jpg
My first point is that not all people would consider that realistic or capturing the essence of the dog. There are other valid, "realistic" perspectives. Some of them may come more naturally to you. Let's just see if we can't free ourselves from the "typical" straightjacket.
But then, why concern yourself with realism? If your purpose is to express yourself, you might turn your back on realism and find it liberating. Even conventional cartoon drawing may have this effect.
Dog Cartoon How-to
http://static.howstuffworks.com/gif/how-...als-22.jpg
If you're stumbling over perspective, I'd like to note that there is quite a body of theoretical knowledge behind it; you'll need to study that to create "3-D" work in the traditional manner. But rigorous perspective is a very new discovery -- most art before about 500 years ago had no perspective at all, as we think of it today.
Medieval Dogs
http://animalreviews.zelica.net/assets/dog2.jpg
Even that may be too difficult or restrictive. Scott Adams, writer of "Dilbert", has got absolutely no idea how to draw -- nor does he much care. He's been ridiculed by "better" cartoonists but he's making money, has a large and loyal following, and has found a way to express himself.
Dogbert
http://www.avtokrator.org/~cwynne/images...ogbert.gif
Perhaps the most successful artist whose technical abilities truly suck is Lynda Barry. She doesn't bother in any way to cater to the conventional taste. She's out of the mainstream market but not by much; her engaging story lines draw readers in. My armchair diagnosis is, she's on the spectrum.
Summer Dog Bingo
http://archive.salon.com/mwt/comics/2001.../story.gif
Lynda has written a comic book on how to draw -- a don't miss. It was given out in 2007 for Free Comic Book Day so you shouldn't have much trouble finding a copy. Her philosophy is: Draw. Draw no matter what, even if all you can do is scribble squiggles over and over. Squiggle enough and eventually you will move to something that tells a story.
If you are like me, you may find that the only way you can be comfortable with any kind of graphic representation is to follow a set of strict geometric rules. If so, suggest you put aside pencil and paper and learn to use a vector drawing package, like Macromedia FreeHand or Adobe Illustrator. Let your obsessions work for you and make up rules both beforehand and as you go along.
Tangram Dogs
http://www1.istockphoto.com/file_thumbvi...og_set.jpg
Or you might want to get into oils or acrylic. Leave all restrictions behind.
Abstract Dog
http://www.ebsqart.com/Art/6215/169926/a...75_275.jpg
Who knows? Drawing may not be for you at all. You might just unlock your visual creativity with a camera. Photography is not all about point and shoot and what you get is what you get.
Dog in Cemetery
http://www.identitytheory.com/visual/pic...metary.jpg
You might consider sculpture, too.
Dead Dog Art Table
http://cache.gizmodo.com/assets/resource...eaddog.jpg
* * *
I can give you a few practical tips that work for me when it comes to creating any sort of artwork.
* Always do something -- anything. Something is better than nothing. You can always smother it in its cradle and start over. You may be surprised at what you want to allow to develop.
* Let yourself spend time. If you're busy, that's hard. Make time. Some people need a schedule. Some of us need to let ourselves be ready to work at any time, to steal minutes from other things. Don't let the hot iron go unstruck.
* Study up. Learn how to search the web for examples (as I've done here), tutorials, and tools.
* Develop habits and templates. I have a set way of beginning every work. Blank paper -- or a blank screen -- is terrifying. Once you get routine stuff down, the blankness is broken and you're on your way.
* Forgive yourself. Give yourself permission to waste paper and to doodle. Do it deliberately, to break the ice. Here's an exercise: Take a fresh sheet -- not of trash but of good drawing paper. Take your pencil in your fist and just jam back and forth a few dozen times, like a six month old kid. Rip out the paper, ball it up, throw it away. Harder than it sounds but the next sheet will be easier.
* If you want to do something formal, practice the underlying skill as much as needed. Don't expect it to come easily. Drawing is no easier than playing a guitar.
* Consider going to a computer, even if you don't want to do geometric work. If you're especially stuck on materials cost, it's a great way to perfect something before committing it to paper. Also, you avoid the endless eraser syndrome, where you just can't move on because you can still see that wrong line, no matter how you rub.
* Compensate for your limitations -- or even capitalize on them. If your eyesight is not so hot, draw larger figures on larger paper. If you have poor motor skills, don't try for fine detail. If you have trouble populating a canvas with a large number of figures, stick to one at a time. Come to think of it, Keith Haring did all of that at the same time.
Dog Barking
http://imagecache2.allposters.com/images...osters.jpg