Wait a few month, John.
Apple is currently developing the Mac part of iCloud Photo Library (Beta). Right now, you can only upload to the iCloud Photo Library from mobile devices with iOS 8, but the new Photos.app, to be released early this year, will make this possible from Macs as well. See: iCloud Photo Library beta FAQ
It will be possible to migrate iPhoto Libraries and Aperture libraries to Photos for cloud storage.
Obviously, all new photos I generate go to iCloud automatically but is there a way to get the thousands of photos that I have gathered over the years to be sent to iCloud.
Be careful - if you are referring to "My Photo Stream", your photos are not stored in iCloud. My Photo Stream is a temporary buffer in iCloud, and the new photos are only kept for 30 days in iCloud, then they will be purged to make room for more recent photos. The photo streams are meant for sharing photos and not as a permanent storage, see: iCloud: Get help using My Photo Stream
If you have saved photos to My Photo Stream, make a local backup of all photos in the stream, while they are still there.