Carbonite is online backup only, so it doesn't really work well for local backups or backups to external drives. You'll still have to handle that yourself. You can try Carbonite for free for 15 days, but after that you'll need to pay up $60/yr to back up one computer with their Home plan, $100/yr to back up one computer with their Home Plus plan, and $150/ur to back up one computer with their Home Premium plan. You can read more about Carbonite's plans and pricing here.
An online backup service isn't much use if it doesn't make the process of restoring or recovering your data quick and simple. For example, a service should offer search tools for finding particular files in your backup. It's also desirable for a service to be able to replicate an entire folder-tree structure so that it can help you recover from bigger data losses. Keep in mind that if you buy a plan that covers just one computer, you may have to transfer the account to a new PC if you ever switch your main device or if you need to restore data from a damaged computer to a replacement.
Carbonite's lowest tier plan, Safe Basic, runs $6.00 /month ($71.99 /year). There are two higher tiers available as well, called Safe Plus and Safe Prime, and run $9.34 /month ($111.99 /year) and $12.50 /month ($149.99 /year), respectively. Each tier is a bit cheaper if two or three years is paid upfront. Plus, they each have a few extras over the base service like external hard drive and mirror image support.
Carbonite is one of the web's most popular online backup services, and for good reason. The Carbonite client runs quietly in the background uploading your data to Carbonite's servers to make sure it's safe in case something happens to your computer. Carbonite can automatically back up documents, music, email, and other files (although it manually backs up video), and grants you access to those files and your archives on your smartphone. Carbonite supports Windows and OS X (although its Home Plus and Home Premier plans only support Windows), and make restoring your files as easy as backing them up. Your offsite files are encrypted to keep them safe from prying eyes, and all of their plans include unlimited storage for your backed up files. Carbonite's Home Plus plan extends its features and allows you to back up external hard drives and not just files on your computer, and allows you to back up full system images. The Home Premier plan includes both of those features and adds automatic backup of your video files, and a courier recovery service that delivers you backups on a hard drive to you ASAP if something terrible happens.
In addition to the 5 GB free option, OpenDrive has one consumer-grade plan called Personal Unlimited. It costs $9.95 /month and offers an unlimited amount of storage space for your backed up files. Prepay for one year at $99 to bring that down to $8.25 /month. You can add an additional computer for $9.95 extra /computer, up to three extras for a total of four.
There are a few common practices for configuring when backups occur. The most common option is on a fixed schedule, such as once a day, week, or month. The second, which we prefer, is to upload file changes whenever they're changed and saved, otherwise known as a continuous backup setting. Services only transfer the modified part of the file in this scenario, so as not to overburden your internet connection or take up unnecessary storage. A third way is simply to upload files manually. Some may appreciate this degree of control, but this method is only effective if you remember to regularly run the backup.