My Bronze Wyrmling familiar has taken the Wyrm of War Sovereign Archetype from Dragons of Eberron, which states that it "becomes proficient with all types of armor and shields, as well as all simple and martial weapons." Okay, great, but how can it even hold those things? Are Dragon paws naturally able to hold and operate items? Do I need to make some alterations to my weapons and shields to allow my familiar to use them? Can it only use them in its humanoid guise (which it doesn't have yet, but that's besides the point?) Or is there something else that I have, as of yet, overlooked?
Draconomicon tells us this about dragons on page 7:
Although a dragon’s front feet are not truly prehensile, a dragon can grasp objects with its front feet, provided they are not too small. This grip is not precise enough for tool use, writing, or wielding a weapon, but a dragon can hold and carry objects. A dragon also is capable of wielding magical devices, such as wands, and can complete somatic components required for the spells it can cast.
So a dragon cannot normally wield a weapon. However, a shield is strapped to the forearm, so the dragon could wield that no problem.
A dragon could use a Mouthpick weapon (from Lords of Madness) to wield a sword in its mouth. You can also use something like graft weapon to bypass the whole "can't hold stuff" bit. The dragon could also trigger a dancing weapon which doesn't need to be held to fight. Also see the magic weapon special ability opposable (Masters of the Wild 28) (+1 bonus; 0 lbs.) and the wondrous item gloves of man (Savage Species 57) (42,000 gp; 0 lbs.).
Serpent Kingdoms and Savage Species also give us the Prehensile Tail feat. Creatures with a tail attack and the Two-Weapon Fighting feat can use it to wield a weapon with their tail.
As a DM I would rule that the dragon requires specialized weapons designed for their physiology. For example their sword would look like an Indian Patta sword. it would satisfy both their physiological description and the archetype's ability.