Yes, spellcasters who use spellbooks can add spells to their spellbooks through several methods. Thing is, those methods? They aren't available to you in this situation.

Rules Compendium, page 160, "Gained Spells":
Spellcasters who use spellbooks perform spell research between adventures. Each time such a caster attains a new level in the appropriate arcane spellcasting class, that spellcaster
gains spells to add to the spellbook according to the class’s description and any restrictions from specialization.
Sorry, can't use this. You don't have an appropriate arcane spellcasting class, so you don't add any spells to your spellbook at level up--unless you start taking levels in the Wizard class, of course.

Rules Compendium, page 160, "Copied Spells":
The spell to be copied must be on the copier’s class spell list.
Guess what, you don't have a class spell list -- not one associated with spellbooks. Magical Training gives you access to 3 0-level spells drawn from the Sorc/Wiz spell list. It does not give you access to the Sorc/Wiz spell list.