where can I find microarray images?
Microarray images (at least for Illumina arrays) will come in .tiff format and are huge compared to the summarized formats (.sdf/.cel). Most places will not archive the raw images (so you won't find them online) and even when you run the microarray, you will often times need to make a special request to output raw images. iirc .jpg images are useless due to compression artifacts.

You can use the proper bioconductor libraries to extract data from the 'exotic' file formats. There are many bioconductor workshops archived online that will go through the steps of microarray analysis.

http://www.bioconductor.org/packages/release/bioc/html/affy.html

http://www.bioconductor.org/packages/release/bioc/html/beadarray.html

http://master.bioconductor.org/help/course-materials/2007/BioC2007/labs/oligo/BioC2007-oligo.pdf