To commemorate the upcoming World Backup Day on March 31, TidBITS Publishing has released Joe Kissell’s “Take Control of CrashPlan Backups” ebook, which provides help for CrashPlan, CrashPlan+, and CrashPlan PRO.

Code 42 Software, makers of the CrashPlan backup service, are marking the day by giving a free copy of “Take Control of CrashPlan Backups” to anyone who signs up for CrashPlan service through Monday, April 2 (Central Daylight Time). Shortly after the promotion ends, Code 42 will send new subscribers email with information about how to get the free ebook.

Those who already have a CrashPlan subscription, or who want to give CrashPlan a try without signing up just yet, can buy the 138-page book by itself for US$10 at .

In “Take Control of CrashPlan Backups,” Kissell helps readers devise an effective backup strategy for CrashPlan’s capabilities, shows how to back up to multiple destinations and restore files from all of them, explains less-common tasks (such as switching to a new computer and seeding a hard drive locally before moving it to a friend’s house for offsite backup), and walks readers through fine-tuning CrashPlan’s many settings.

All three consumer and small-business versions of CrashPlan — the free CrashPlan and thesubscription-focused CrashPlan+ and CrashPlan PRO — are discussed, with relevant differences called out. (The book doesn’t cover CrashPlan PROe, the enterprise version.)

Kissell has written many ebooks in the Take Control series. He’s also a senior contributor to “Macworld” and senior editor of “TidBITS.”