Not sure what you mean by figures and concepts. Figures as in humans? Concepts as in architecture? Concepts as in character models? Are you an absolute beginning? Stick man drawing? Computer graphics? No one can tell you "where to start", because we don't know how much you know or where you've been in regards to the field of study.
The place that I know for art is
DeviantArt. Talk to the artists there and ask for advice. Seriously. I'm no artist. I like it and I used to be into it but I'm not good at it.
I never went to school for art.. Other than taking it in high-school (years ago for game design). Drew this last year:
http://i.imgur.com/oaeX08j.jpg?1 while sitting in a boring Mech. Eng. workshop. So I'd say I learned something? I guess I can say what I was taught in school and hope that helps.
You want to draw concepts (character/cartoon models) and figures(humans)? Then I'd suggest starting with Anime. Get one of the kneed-able erasers and set of the fancy HB pencils.
What my teachers made us study:
Shapes & Colours.
Study of Complementary colours.
Blending of Colours & Paints.
Forming new colours using only the primary colours.
Art History (extremely boring).
Perspective (3D vs. 2D on paper or canvas).
Crafting with clay and other pottery tools.
Practising lighting and shading using pencils, charcoal, erasers, etc..
Practising contour lines.
Painting with oil (hard as hell for me).
She made us draw people (actual humans, not cartoons). The reason for this was to study human anatomy and make up. We had to learn how to draw a nose without actually drawing out the thick lines and creases, but instead drawing a nose from just shading and lighting alone.
All in that exact order.
Rarely do I ever come across someone that wants to be an artist (extremely hard field to be very successful in because if your art doesn't sell.. well ={ ).
But again, I'd suggest starting with Anime (or people, depending on which you prefer). Why? You actually learn all the basics of human anatomy in order to make the faces, fingers, eyes, nose, ears and all the difficult parts of drawing realistic characters and people.
Once you get that down, you can almost draw anything. Especially figures. I say this is as good as any place to start because drawing faces, fingers and hands, eyes and stuff like that require attention to detail, hard work and effort, and you're going to have to make it convincing. Just tackling this alone will make you quite a decent artist once you get it down.
Another thing is: Learning to draw from references or from taking a single glance at an object and remember a ton of details about it, in order to draw it accurately. Could also practice that.
Seriously though, ask guys on imgur and deviantart. I can ask on of the graphics designers I work with to check out your post I guess. They're amazingly good.