Transform your photos into electronic files with a desktop scanner. Click on the scanning software option to save them as JPG files. For the best image quality, scan your pictures at 300 dots per inch by selecting that option in your scanner software.
Save your new electronic files in a folder labeled "Scanned Photos." Keep the folder on your desktop.
Print your images on a desktop color printer. A black and white printer can suffice. Print on colored paper to add more variety to your black and white images.
Trim away excess white paper on the edges and crop your pictures to the size and shape that you desire.
Attach your images to the picture frame with rubber cement. Allow them to overlap in places, if you wish. Print words, names or dates in a word processing program and cut and paste them, too. When completed and dried, cover your picture frame with a coat of artist's varnish to protect your collage.
Log into your Picasa account (see Resources) and select the photos you'd like to include in your collage.
Click the "Collage" button in the Photo Tray. You can also create a collage for all photos contained in a folder or album by clicking the "Create Photo Collage" button located in the folder or album header.
Select the "Frame" mosaic option. You can create a mosaic of your selected images, all surrounding one prominent center image. Change the center image by clicking your desired center image, and then clicking the "Set as Frame Center" button.
Click the "Clips" tab on the left side of the collage creation page to add more photos at any time during the collage creation process. The folder of photos you've been working with will be available under the "Clips" tab. Select the photos you'd like to add, and click the (+) button to insert them in the collage.
If you want to add photos from a different folder, click the "Get More" button to find additional photos in your library. Select the photos from your library. After you've finished, click "Back to Collage" in the "Photo Tray." You should now see your additional images displayed on the Clips tab. Select the images you'd like to add, and use the (+) button to add them to the collage. You can use the (x) button to remove images from the "Clips" tab.
Click the buttons above and below the collage to help select and arrange the photos included in the collage. To remove a photo from the collage, select the photo in question and click the "Remove" button above the collage.
When you're satisfied with your work, click "Create Collage." Alternatively, click the "Desktop Background" button to create the collage and set it automatically as your computer desktop image. Once you've created your collage, you can share it with friends by uploading to Picasa web albums, emailing or printing it in high-resolution.