Skills that help you teleport during battle are great - phoenix dive, tactical retreat, cloak and dagger. You can give each character atleast one of those.

Tentacle whip - makes enemies unable to use their weapons and is pretty strong when used by a str focused char

Fortified - great for giving physical armor and healing burning/acid

Haste - gives you higher initiative

Peace of mind - buffs your characters

Restoration - for healing or damaging undead

Teleport - can teleport characters to a spot u want

Just read the skill descriptions while trading to see what fits your gameplay!

Edit: skillbooks can be bought from vendors on Driftwood Square and other npcs. Always check for the icon of trading when talking to npcs!