Head on over to Apple's website or the Apple Store app on iOS to reserve the Watch you want, just like you would an iPhone. Apple has allowed prospective buyers to mark their favorite Watches online to speed up the selection process.
Not sure which watch to buy Friday is also the day Apple opens up Apple Watch appointments at its retail stores around the world. You can book a time slot online, similar to making a Genius Bar appointment. During the sessions, you'll get a chance to try on different styles and fits of the Watch and see a demo of how it works. You won't be able to order one in-store--Apple said Thursday that it will only sell the Watch online at launch due to limited inventory.
Apple will only have Watch Editions available to try on at select locations, so make sure you do a search in advance to see which Apple Stores are stocking which models.
If you're preordering without trying the Watch on first, we've got a guide to picking the best Watch for you. Still trying to figure out whether to buy an Apple Watch at all See our pros and cons here. And our Apple Watch FAQ has everything you need to know about the Watch and its many, many features.
If you preordered, let us know in the comments if the experience was smooth sailing or ridden with glitches. Also, we want to know which Apple Watch model, size, and band you picked, so spill the details.