I usually mix both. When I first got my Singer Fashion Mate, I tried following a video for bobbin winding, which helped me start quickly, but when I had skipped stitches later, I had to dig into the manual for troubleshooting tips. The diagrams were way more detailed than any video I’d seen. I like having the official manuals bookmarked, and I often use
https://manuals.online/singer since it’s handy to pull up on my tablet while I’m sewing. For me, videos are great for visual learners, but the manuals cover things you won’t want to miss.