If you create a Firefox account, I believe you can sync your bookmarks as needed to all your devices. As for update/store in the cloud...I'm just not gonna go there.

I tried the built-in Firefox Sync a long time ago but decided it wasn't for me. I don't remember why.

On my home network I sync Firefox profile directories.

I use a utility called rsync but it's not for everyone.

Likely the easiest way is to use Firefox Sync but if you're comfortable with learning file locations, you can copy and paste either the entire Firefox profile or just the files you're interested in. For example, Firefox bookmarks are stored in a file called "places.sqlite". If you copy that file from one of your computers and paste it into another computer, you'll have your bookmarks from the first (master?) computer on the second (slave?) computer.

Likewise, to copy the passwords remembered by Firefox, you just need to copy two files from the master computer/profile to the slave computer/profile.

"key4.db" and "logins.json".

Personally, I find it easier to copy the entire profile..

To locate your Firefox profile: https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data#w_how-do-i-find-my-profile

A few of the important individual files: https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile#w_your-important-data-and-their-files

Possibly an added benefit of knowing where your Firefox profile is located is that you can make a "just in case" copy of it.

I'm on Linux but on Vista I'm sure you can probably right-click the directory and select something like "Add to zip folder" or something like that?

If your profile later gets corrupted you'll have a backup. Just unzip the backup and replace the corrupt profile.