My Favorite place for d20 Books
There’s many places to find source books for the d20 system, however DriveThruRPG has proven the most reliable over the years.

Check out their source book offerings here.

ScaleCore Maestro

In an inn, not all that far away from whence stood the Free City, a small gnome with golden scales and a pair of draconic wings was playing his lute, and singing the story of two sisters and two brothers who together would do everything in their power to stop the dark army who ravaged the lands.

His music sparked illusion magic who, for a moment, calmed the hearts of all those who had lived through the carnage of that dreadful night…

Race

Gnome

Class

Bard 10/Dragon Disciple 10

Ability Scores

Str 8/Dex 16/Con 16/Int 10/Wis 10/Cha 16

Skills

Knowledge(Arcana) 8

Equipment

Chain Shirt, a Rapier, any musical instrument, a Light Crossbow

Goal

As a core class, one of the builds must use core only material. A Bard/Dragon Disciple make possibly the best core only jack of all trade build, highly capable skill-monkey, a more than decent variety of spells, both for battlefield control, debuffs, buffs, healing, even damage, the ability to fly, good melee damage via natural weapons, and a breath weapon you keep in your backpocket. And still capable at long range with your crossbow, and surprisingly tanky too with d12 HDs and a high Con score. There are few roles you cannot cover(if at all, which I would argue that no there ain’t).