Pretty sure the 1st book shows more channeling than that...whatever Moiraine did to sink the Ferry, her trick for supressing exhaustion, Wards (I think?), normal Healing, and everything Rand did at the end by harnessing the Eye.
Its been a long time since I read the first book of WoT, but lets see.
I think Moiraine throws around fireballs and such at the start during the trolloc attack. Then she uses ordinary One Power healing to heal the wound on Tam which was corrupted with evil or somesuch (could help Dumbledore if he decides to find the Resurrection Stone early). She also manipulates water to destroy that ferry. Oh, and I think Moiraine creates some anti-evil ward to protect a house when they are in Shadar Logoth. Egwene does some minor tricks like conjuring fire and such, but nothing usefull.
Rand subconsciously removes exhaustion from a horse, physically moves a mast (or the movy thing attached to one) to knock a trolloc unconscious and summons a bolt of lightning (the most destructive feat I think) to wreck an inn so he can escape. Oh, and Moiraine does some evil containment thingie with Mat and that major artifact level super-evil dagger.
At the end, Rand uses EotW to do all sorts of really major stuff sufficient to anninilate an army, but he was powered by a major artifact at the time so GM would probably nix any of that.
The more "advanced" WoT things start from book 4 onwards, when Rand starts becoming more efficient and experienced, starts stealing knowledge from LTT and when the other forsaken (who unlike Ishy don't use evil corrupted power) start appearing. We also start to see the Aes Sedai do more stuff around that time.
Ultimately though, I don't know if theres anything in Wot that would be all THAT usefull for Harry. The biggest advantage WoT magic has over HP (IMHO anyway) is the fact that its cast purely mentally so no need to move a wand, aim or speak words. However since it would not work like that for Harry due to the convert-to-wand-spell, I don't see WoT being all that usefull.
The one exception that occurs is traveling. If it works exactly like it does in the WoT books then that would be most usefull I think, since opening a stable "door" between two locations that anyone can use and which can even be left open for hours/days has lots of usefull applications that pure teleportation like apparition/D&D Teleportation does not.
Not to mention trolling people by hitting them with their own spells.
Until, and unless, the OP says otherwise, we are not taping into the power of any dark gods, even if that is how that form of magic works.
The only exception I can think of would be summoning spells.
At most, Ishamel's version of healing would cure the insanity, but cause massive physical pain in the process.
Depends on the GM. Could be that any spells that come from dark god in WoT would be considered to be extreme dark magic in HP, with potential problems. However Ishy is quite literally the only one who uses them (since they drive the user quite mad). Unfortunately Ishy is the major WoT antagonist for the first 3 books.
