I've drawn out the eighth rests/notes- is there any convention about where to position rests relative to the notes? here's an image of what I've done http://imgur.com/on9WYJ5
(also thank you for addressing the imitation stuff)
looks great. the note heads might not need to be so big and full, but that is something you will get the hang of as you continue writing. of all your rests the first one looks the best, but even that doesn't need to be as perfectly drawn as you have drawn it. if you start to write a lot of music you will find quicker ways of just zinging everything in. note heads usually turn into almost a slanted line. anyway, it looks great. the alignment is good. usually alignment should adhere basically to the timing, but in some cases you can stretch it a little for readability. for example if you have a bunch if 16th note crap on one side of the bar and nothing in the other side sometimes you may stretch the complicated side out a little bit. anyway, that looks great. 16th notes are just like 8th notes, but they use 2 flags instead of 1 (or a double beam instead of 1.) ok i think you are good with rhythms for now. i think the next step is to figure out the pitches. the next step might be different depending on what instrument you are most familiar with. if you are not familiar with the layout of notes on a piano, learning to read might be a total nightmare. i'm not sure. but try putting notes on every line and every space. the notes in your example are perfectly aligned in the space (that would be A in treble clef). when a note is on the line, it should be the same size, so the top and bottom of the head should reach about halfway thru the space on either side of the line. i would say, make a bunch of notes in a row, going up. just like you would write a series of quarter notes, but don't use any stems, and don't use any bar lines. ignore the time for now, just line them all up. kind of like an ascending staircase of notes. start anywhere (probably on the bottom line? or you can even start with one just below the bottom line if you want) and put the notes in, going up. line, space, line, space, etc. news flash this is the white keys on a piano. i will tell you which ones they are later. i hope this makes sense