There are only 3 "wild magic spells," and all Wild MAges know them automatically--you don't need to scribe a scroll. Chaos Shield and Improved Chaos Shield make your Wild Surges less likely to have negative effects, and Nahal's Reckless Dweomer pretty much guarantees you'll get a Wild Surge of some kind. Go to either
www.planetbaldursgate.com
or
wwww.gamebanshee.com
then go to their Baldur's Gate 2 section, and from there to their Spells pages.