Putting stitches on stitch holder

I am knitting my first sweater in the round, using this pattern: http://istex.is/Files/Skra_0051195.pdf
I have now finished working my first sleeve and the patterns tells me to “place 10 sts underarm on st holder”. I was wondering which stitches to put on the holder. Would this just be the first 10 stitches of the next round?
Also, since I will be needing the needles to work the second sleeve, what should I do with the remaining stitches?

Thanks!

These 10 sts are going to be part of the underarm. There’s a sleeve marker and increases on either side of the marker so you want to center the marker at the underarm. To do this, knit the last 5sts of the round and the 5sts of the next round. Place these sts on a holder. You can use scrap yarn for this if you’d like. You can also place the remaining sleeve sts on a separate piece of scrap yarn or on a spare needle if you have one until you finish sleeve 2. This way the sleeve is ready to knit the next round when the yoke is joined.