How do I secure individual documents in Lion?

Question

I'm sure this question has been answered but I can't seem to figure out how to secure individual documents in Lion.
Here is what I'm trying to do;
I'm scanning or saving from various sources certain forms or files to Lion and keeping in documents. Which works great, but I can't figure out how to secure these documents individually.
Would someone mind pointing out my error and perhaps recommend a resource where I can learn more of these basic Mac operations?
Thanks gang,

Answer 1

Yes Grasshopper.
(the previous suggestions is good, too)
1. open automator (it's in applications)
2. when it asks you what you want to make, pick service.
3. at the top, where it says "service receives selected", pick files or folders
4. where it says "in", pick Finder.
4.1 on the left, under library, select files & folders
4.2 to the right, pick New Disc Image and drag it over to the right
5. Size: Size disk image to fit contents
6. check encrypt
7. when done: unmount and return the image file
8. close or save the window; give it a name, like "encrypt".
9. try it out. Select the file you want to encrypt in the finder; control click on it to open the contextual menu; scroll down to services, and pick the service you just created.
10. It should make a disc image and ask you to create a password.
11. when you open the disc image, it will ask for the password, and then a virtual disc (looks like a little generic white drive) will open. In that virtual disc will be the decrypted file.
12. you can delete the original file and work from the decrypted version in the virtual disc.
13. When you close the decrypted version and either eject the virual disc (by dragging it to the trash) or restart or shut off your computer, the changes should be saved in the encrypted disc image.
14. let me know how it works.