ummm... this is a good start, but i highly highly reccommend diving into photoshop immediately.
-youre gonna have to use it eventually, unless youre nuts good with MSpaint.
-its much much easier to draw things out, even things like what you have above.
-even just the basics of photoshop are enough to get you by.
-layers allow you to move buttons around! very nice if you dont want to redraw a whole section of stuff...
-photoshop allows you to save in transparency (.png files) if youre into that and want changeable backgrounds.
>>thats really it for now, im sure theres more reasons, but again, very good start on a better tutorial- im just trying to help and save time as a long time skinner....