Keep at it and don't give up.
I like the ideal of a hyper-femme Macintosh mascot, the glasses are a nice touch.
Since you were kind enough to ask for critique I'll toss my two cents in. Bear in mind that I'm pretty rusty and an extreme (and not in the cool bungee jumping 90's way either) amateur as far as art goes.
Get your hands on a white rubber eraser they work wonders for removing pencil. Erase lines gently in the same direction to avoid smearing.
Pencil is a great tool for sketching out the figure lightly before inking or going for a final render with darker lines. Try the lead stick mechanical pencils so you don't have to constantly sharpen although regular number 2's will work if money's an issue.
Scrap paper is great for figuring out positioning by making smaller roughs however for work you're ready to show I'd suggest blank printer paper. Notebook lines and hole punches distract from what you're trying to render.
Draw from life. As weird as it sounds a solid knowledge of how people move and are shaped in reality will make your fantastic interpretations that much more convincing. If you can't find someone to pose for you, mind you as comfort levels and access allows, then a mirror is always handy for figuring out how something might look from a certain angle.
Shadows and lighting also add a lot to the 'weight' of a figure. It gives the shapes added depth as well. IF you're not entirely comfortable working in color yet try shading in greys to black.
Larger sheets of paper like pads of newsprint allow you to free up your pencil. If the very act of drawing is physically uncomfortable at a certain angle don't hesitate to move the paper upside down if you have to.
There are some really nice art tutorials on this very site. Many of which don't require expensive programs.
Good luck.
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