Hello all ~
I, too, am a newbie and have found "Cross Lace Cord" by Jimalax to be a reasonable cord to use. It comes in a wide variety of colors. Has stood up well for the key fobs and THs I've made, retains its color over time and is reasonably priced. Service was fast and accurate, they were more than happy to send along samples of the three sizes carried and if you order is above $100US, then shipping is free.
http://Http://www.jimalax.comI got tired of trying to locate reasonably priced (and best size) accessory cord at my local climbing/outdoor store, paracord had too much slop and play in it for what I was working on and when you purchase 100 yd spools, it takes a while to run out (which is very frustrating when it happens at 2am)
I measured the diameter of the cord for Don B this past summer and will dig out that post tonight and post here.
The only "issue" i'd note with my batch of the JimaLax cord is that there are minor differences in OD depending on color (Black and White are just a tad larger), the yellow color will come off on your hands as you work, but no issue staining clothing, and some colors are a bit "stiffer" than the others.
Hope this helps ~