Sweetie Belle/Spells

Accelero
In the episode Surf and/or Turf, Sweetie Belle is seen running very fast toward Harmonizing Heights. Before she does this, her horn is seen glowing, so it can be presumed that she is using the spell of Accelero.

Levitation Spell
Every unicorn in the series has been seen using a levitation spell. Sweetie Belle is not an exception - she uses it first in Twilight Time, and she gets better at using it in Crusaders of the Lost Mark (my favorite episode!).

Spells That Only Affect Others
Unknown.

Poké Transformation
Sweetie Belle asked Twilight for a spell to communicate with her Pokemon. Twilight found a spell to let her temporarily transform into a Pokemon and the other way around. It lasts for an hour by default, but if she concentrates enough, it can last for as long as a full day. She can even turn other ponies into Pokemon!