.Tolkiens quote "...a bit of a magician..." doesn't imply, that there is the possibility to just learn magic spells for humans. In this thread the topic is to develop more Spellcasting Abilities, a new Race or a new calling. And that kind of contradicts Tolkiens spirit of Middle-earth.
Actually, the quote is vague enough that it could imply that. Even so, it is pretty ambiguous.
.I'm not saying, there is no magic to be fond in Men. The Numenorians and later the Dunedain were able achieve great works, but it didn't had to do anything with Wizard-like spells. If you look at Aragorn's abilities to heal, the gift of foresight and his "Ways of the Wild", you could simply assume, that this is due to the fact, that his ancestry includes powerful Elves, Men and Maiar.
There were already two Middle-earth games before TOR: MERP and the Lord of the Rings RPG. Both handled Magic differently than TOR. The first mentioned had D&D-like Spell lists, the second was more on spot, but also gave the possibility to play Magicians, and now TOR goes the "puristic" way.
If you want to include Magic in the Form of Spells, do so, it is your game. You just need to take the Spells from the LotR RPG, and let them be learn via a Mastery (Virtue). The first Spell grants access to the generell "Class", like Nature, Fire etc. The next Spells could just cost 1 AP, similar to the Wood Elf Magic in 1e. You could make up new Callings like Magician, Witch or Sorcerer and grand them access to specific spells. A Spell could cost 1 Hope, grant a Magical Success (what else?) and would need a Skill Roll. If nothing fits, use Lore, Wisdom or Valour.
For me personally that would be too much, but if people have fun with it, why not?
I'm actually not trying to add spells to TOR; I'm just acting as the Devil's advocate.