one thing you have to remember in keeping it behind though is that it also has to go UNDER the needle. You may have it behind but if it is pulled over the needle it will still look like an extra stitch.
a lot of people just slip that first stitch off the needle on every row and then it will make for a really nice edge. i tend to just make sure that on the SECOND stitch, before i wrap the yarn, i give it just a smidge of a tug to tighten that first stitch. you have to be careful not to get into the habit of doing it on every stitch or your work will be tight...just on that second stitch. i also give the work a smidge of a tug down before i start each row to kind of straighten out that last stitch of the row too.
btw...the problems you are having are normal beginning knitting problems! just keep goin'...you will get past them fairly quickly!