I know you're looking for something shorter than book-length, but I've been scouring popular evolution books in hopes of presenting one to my creationist parents at some point. Here are some of the most popular:
Dawkins - The Greatest Show on Earth
Strengths: Sufficiently-technical but still simple explanations of how we measure genetic relatedness, the Lenski E. Coli study and its implications of intelligent design and historicity of mutation, how embryological development and "blueprints" (ie, Hox genes) factor into the big picture, the limits of evolutionary growth (in terms of marginal benefits and costs), "purpose" in evolution (very similar to An Alien God), and how fossils are dated.
Weaknesses: Pretty much everything else. Dawkins has a rambling writing style, focuses on controversies that are best left ignored when talking to someone who doesn't even understand the basics (ie, the exact origin of turtles), and spends a good portion of the book trying to lower the social status of creationists.
Coyne - Why Evolution Is True
Strengths: Absolutely the best explanation of the evidence for evolution from biogeography I have ever read. Since most creationists outright ignore this evidence, it will be surprising to the uneducated, and therefore more convincing. Good (but not great) explanations of how fossils are dated. This is the only book I've seen mention that radiometric dating has been verified by other methods (ie, fossil coral rings), which is another surprising argument that creationists usually ignore. Good, brief explanations of genetics and fossil evidence. Good explanation of vestigial organs and "bad design." Great chapter on sexual selection theory, its predictions, and its evidence.
Weaknesses: The focus of the book is definitely on facts that creationism can't explain, so every chapter has at least one moment of, "How can creationism explain this, except by pure ad-hoc?" This can come off as combative. Some of the scientific explanations are so simplified as to be nearly false--for instance, Coyne comes very close to implying that fossils must be sandwiched between two layers of igneous rock to be dated properly, when of course many situations (including an intrusion of igneous rock) will also do.
Prothero - Evolution: What the Fossils Say and Why It Matters
Strengths: Goes through most of the major transitional series, with pictures and diagrams, to show why they are best understood as transitional fossils. This includes series that creationists usually ignore, like the evolution of triceratops, long-necked dinosaurs, ichthyosaurs, brontotheres, "small shellies," early vertebrates, and several microscopic fossils. Great explanation of cladistics. Great chapter on the origin of life--instead of saying, "Evolution doesn't address that," Prothero takes the reigns and says, "Here's what we know, chemically, and here are the current working theories." Great chapter on the Cambrian explosion--which he calls the "Cambrian Slow Fuse," as he points to the 100 million years it took to go from small shellies to the worldwide proliferation of trilobites. For your purposes, there is a discussion of the compatibility of evolution with some religious views.
Weaknesses: Prothero is a student of Gould, so the book wastes a bit of time discussing (bad) philosophy of science, "separate magisteria," and punctuated equilibrium. (Not that there's anything wrong with punctuated equilibrium, but I think its presentation confuses the discussion in a way that would be better remedied simply looking at the charts presented in this video.) Prothero also spends some time gloating over one of his debates with Duane Gish. This is entertaining to someone already sold on what he's selling, but would be off-putting to a creationist.
If anyone has more recommendations, I'll check them out. I have yet to read Eugenie Scott's Evolution vs. Creationism: an Introduction, the NCSE's evolution primers.
All that it took to convince me, even while I was still a Christian, was two college-level geology courses and Talk Origin's Index to Creationist Claims, wherein I learned the tendency of creationist authors to lie, lie, lie, lie, lie.
I have a creationist friend with no particular rationalist or scientific training. She recently asked me to send her a "list of evidence for evolution that persuaded me." After some prodding, it was revealed that she's getting into an argument with another friend of hers who believes in evolution. I'm assuming that she wants the experience of arguing with someone who's on level footing with her. It seems like a good opportunity to broaden someone's mind in a more general way that'll benefit them in the long term. I don't particularly care whether she believes in evolution (it probably will not impact her or the world in general if she changes her mind about it). But I'd like to phrase my e-mail in a way that's most likely to cause her to re-evaluate her worldview.
Subgoals related to this:
1. Point out that "losing" an argument can allow you to learn things, and if you honestly care about truth you'll try your best to evaluate ideas from other points of view and consider what it would mean if they were true. Do this without sounding condescending.
2. Give her a line of retreat by proposing that evolution is compatible with the Original Sin interpretation of genesis (which is very important to her and I would never attempt to argue against).
3. Give as much background as possible on the scientific method.
4. Still manage to focus the bulk of the e-mail on the most persuasive facts supporting evolution, otherwise I'm obviously not satisfying the criteria she actually gave me. I don't mind taking advantage of her request for my own purposes, but only if I'm actually helping her with her stated goal.
5. Specifically show why macroevolution is not only possibly but likely. (I'm pretty sure she either already believes or could be easily persuaded to believe in microevolution)
6. DON'T focus too much on why creationist arguments are flawed (she hasn't even used any yet, and it sends the wrong message about trying to actually figure out what the truth is)
7. Accomplish everything in approximately 3000 words, without using jargon, designed to be read by someone who's mental architecture isn't particularly adapted to rationalist thinking. (Most people aren't.)
I believe I can do a decent job myself. But it'll be a fair amount of work, and I want to know if anyone had a recommendation for a particularly good essay that I can either link her to or borrow pieces from. I might also include a link to a page of common bad creationist arguments and why they don't make sense.