One of the touted advantages of tablet computers is that they can be used for reading books and magazines without needing to carry as much heavy paper around. (Dedicated ebook readers with "electronic ink" are easier on the eyes than a light emitting screen, for longer periods of reading, but carrying two devices around doesn't exactly help reduce the weight you're carrying around....) I've been following various online publications for a while (such as the online f/11 magazine) and was looking for a way to read them on my iPad. Some of them can be read online (and a 3G SIM in the iPad helps with that), but others are more conveniently read by downloading them and reading them offline.
Apple's iBooks app (free install) (on Wikipedia) is the most bundled answer to this problem. It's not installed with the OS by default, but is produced by Apple and available in the iTunes app store for free -- and the ability to sync external content is included in iTunes (as well as purchasing books via iBookstore). iBooks supports ePub format eBooks, as well as PDF files; and several "download and read offline" magazines publish via PDF files. The process for adding external content like PDFs to iBooks isn't entirely intuitive, so I'm documenting it for future reference:
Sign in to the Apple iTunes app store (creating an account if necessary).
Install the iBooks app (needs iOS 4.2 or later, which should cover most iPads), read for sync onto the device.
Add one or more books (PDF, or ePub) into the iTunes Library (File, Add to Library) the same way as adding music (or podcasts); when added a "Books" category will appear in the Library (along side Music, Podcasts, and Apps).
Connect up iPad device (the "wireless sync" added in iOS 5 and recent versions of iTunes is very handy here, especially if you usually have iTunes running for other reasons -- eg music via AirPlay).
Go to the device's sync page, and choose the "Books" tab. Enable syncing of books, and either choose "All books" or choose "Selected books" and then work through the books in the iTunes library selecting which of them should be sync'd to the device. ("Books" are ePub files; PDFs are treated separately by the iTunes sync process as well as the iBooks app; Apple calls PDF files "Digital Booklets".)
Sync the changes on to the device.
Open iBooks on the device. The new files (eg, PDFs) should be automatically found. New PDFs will appear in the "PDFs" collection (and presumably new ePub files will appear in the "Books" collection). It is possible to create new Collections (Collections/New), and then to move new files into the new Collections (Edit, tick Books, Move, select new Collection). But it appears not to be possible to influence the order in which the PDFs are displayed (so hopefully the automatic order, based on filename or creation time is appropriate).
Additional PDFs can be added via the same sync process, and items removed from the device via the same process. It'd probably be useful to keep a separate copy of any downloaded/purchased content that you want to keep long term (ie, outside the iTunes library) as a backup. See also Apple's FAQ on iBooks.
On the Photography front, in addition to f/11 Magazine, the Strobist end of year round up also pointed at Michael Kelley's site (via a write up of his "two speedlight" architectural photo process). The site has not only fantastic arcitectural photos (made with love!), but also a blog including a handy list of books for the working photographer. (The Strobist also described how the NZ Symphony Orchestra promotional photos were created by Chris Waind, who also has an Etsy Store.)
And Ken Rockwell points at the 1x year end book for 2011, a stunning "best of the participating photographers" limited edition book (small versions of about 50 photos are online; the book has another 150 or so, and always sells out quickly). They also have a large set of tutorials, mostly along the lines of "how I got this photo" which are worth reviewing. Because the 1x site is curated by professionally photographers (they say only about 1 in 20 of the photos uploaded are selected for display online, let alone in the book) the quality is very high.
Metafilter also points at some wonderful photos of London without people taken on Christmas morning. My favourite (and that of many others, it seems) is an early morning reflection of St Pauls.)