In Power of Three by Diana Wynne Jones, many magic spells can be done by anyone who learns the appropriate incantations. (At least, anyone in the races called Lymen and Dorig. I don’t remember if humans can. It’s been a long time since I’ve read that book.)
Clarkian magic. It’s just sufficiently advanced technology.
At least the B5 Technomage trope acknowledges that it’s not really supernatural, even if it intentionally drapes itself in the trappings of magic.
I think Gerald uses some Words at one point, so yes, anyone: humans are just ignorant.
Tim Powers tends to have “hard work magic” in most of his novels. Although some people are specially talented, or born into circumstances where they have a magical advantage, generally people who are aware that magic exists, and how the rules work, can get a fair way there through sheer perserverence
The Percy Jackson stories are an example of such; magic items in that universe are useless to humans; in fact, humans can’t even be harmed by magical weapons.
The magic system in the Demon Cycle series by Peter Brett involves runes that anyone can use. The clearer and more exact the rune is drawn/engraved/tattooed, the more power it will convey. Practice and knowledge are the only hard requirements for humanity.
In the Dragon Age games, the ability for magic is innate and it’s possible for people born with “the gift” to do it without any formal training - but mages don’t dream and instead consciously enter into the spirit world every time they sleep, and their power is like a beacon to all kinds of evil spirits that seek to possess them and turn them into what the church calls “abominations”. Anyone with signs of having the gift is taken from their families and raised in convents under church control where they’re trained on how to resist the spirits, and if they’re deemed to not be strong enough or dedicated enough in their studies they’re “made tranquil”, which is basically a magical lobotomy that permanently severs them from their magic but leaves them incapable of feeling emotion.
The qunari, a race of gray-skinned ten-foot-tall horned people who practice a sort of militant Confucianism, on the other hand, don’t consider their mages to be people at all - they cut out their tongues, give them a name which in their language means “dangerous thing”, and use them as living weapons.
Marvel actually has it both ways. Any normal human can study magic and become a proficient spell caster, but its hard and not everyone is cut out for the difficulty and sacrifices. But there’s also people like the Scarlet Witch, or Ilyana Rasputin, who are mutants whose mutant power involves manipulating magic in some way.
In the Unbeheaded King series by L. Sprague DeCamp, it seems that performing magic is just a matter of study and knowing the correct procedures. In the opening scene of the first novel The Goblin Tower, the hero Jorian escapes from his world into ours (our world is the afterlife of his) with the help of a wizard, but then returns to his world by merely uttering an incantation.
Strange Academy has one (but only one) “main character” student who has no innate magical ability. (Calvin.)
Along these lines is included the “planetwide all-pervasive energy field” version of magic. Examples would be “The Ship Who Won” by Anne McCaffrey & Jody Lynn Nye, and “The Aeronaut’s Windlass” by Jim Butcher. The latter is an example of a variant on who can use magic: in principle anyone could choose to become a devotee of magic, but like joining Dune’s Navigator’s Guild, doing so quickly dominates every aspect of your existence to the point where magic users are no longer normal people.
After further review, Sanderson’s Stormlight Archive series might fit as well. There is no inate “born with” ability to attract a spren, rather it happens based on how the person acts. So you can’t really just study your way to magic, per the title, but it IS available to everyone, per the OP.
Is that right? My memory is too hazy. I recall that in the beginning it is mentioned that plenty of magic used to be done in the past, but there are various reasons why it hasn’t worked for a while. Maybe it was what Stanislaus wrote, but that opens up more questions.
I hope you have made arrangements for your next of kin to notify the SDMB, if that were to happen. 
Comic books always have it every way, and then some, depending on who’s writing any given issue.
I’m told that passing gas in front of an angel is the easiest way to offend them. The ritual requires you to be on a strict vegan diet that week, so I’ll have to remember not to overdo it on the beans. 
You are full of surprises, Smapti. I had a friend who tried that in high school (we all knew that one kid in high school who was all into medieval Kabbalistic ritual, amirite?). Sounds fascinating and I hope you do a thread keeping us posted.
I’m not 100 percent sure either. I guess we need someone who has either read the book recently or has a better memory.
I only learned about it recently and the more I learned about it the more compelled I’ve felt to take it on. I’ve been comparing both English translations (the 19th century one by Aleister Crowley’s frenemy Samuel Mathers, and the more recent one by Georg Dehn that uses an older more complete German copy of the text) to decide how to best go about it. I’ll be starting in late April and thougb I obviously won’t be posting very much while I’m doing it I do intend to make some Youtube vlogs about the experience.
Just checking… he didn’t screw up like Aleister Crowley did and accidentally summon a sea monster into a nearby lake, did he?
(Apparently one of the more out-there stories about the Loch Ness Monster is that Crowley created it by accident when he abandoned the Abramelin halfway through.)