If you're interested in designing aran sweaters, there's really only one book you need to have on hand--Janet Szabo's Aran Sweater Design. She covers EVERYTHING! For instance, I'm aiming to design a bottom-up raglan aran. Naturally, one gravitates toward EZ's percentage system, but how do you make that work when the body totals are much higher than they would be in stocking stitch because of all the cabling, and the sleeve is likely to have rather less cabling and more filler stitches? The answer: apply the percentage system using inches instead of stitch totals. Brilliant.
I'm done the extra long cabled ribbing (above) and about to launch into the serious cabling work. This is Quince's Lark in "Frost", not blocked yet and feeling oh so squishy!