Anything by Elizabeth Zimmerman will help you learn construction, her Percentage sweaters are knit bottom up and the numbers use a percentage of the chest measurement to knit with. The Sweater Workshop by Jacqueline Fee uses her methods and details them a bit more. Knitting from the Top down by Barbara Walker will explain several methods for knitting not just raglan or yoke sweaters, but set in sleeves too. She also has 4 stitch dictionaries. Custom Knits (Wendy Bernard I think) has a few patterns with some info on how to change them and change any pattern; the back has a brief overview of the BW book. Finally I think there's Sweater Design in Plain English by Maria Righetti (sp?). Any of these can usually be found or requested through your local library so you can look through them to see which you'd like to purchase.
The EZ books also give 'recipes' and construction techniques for hats, vests, shawls, mittens, blankets, baby leggings and other useful items.
sue- knitting heretic