Here you can find some handy astro related reference material:
Dr. Michael Richmond’s most excellent website & his talks for ASRAS (posted March 2024)
Stellar Starting Points – Frank Bov (posted Oct, 2018)
asras-ionia150 (history of Farash Center slide show)
History of Louis Swift article (PDF) (posted Oct, 2016)
astronomy101 (posted Oct, 2016)
astronomy101_2 (posted Oct, 2016)
astronomy101_3 (posted Oct, 2016)
astronomy101_4 (posted Oct, 2016)
Messier Objects Poster (link to image) (posted Oct, 2016)
Link To great tutorial for processing with PIXINSIGHT from Andy Chatman: