Start here. From the beginning.
http://www.pinrepair.com/sys1/index.htm

For this era of machine, some playfield restoration links:
http://www.passionforpinball.com/jjresto.htm
http://www.pinrepair.com/restore/jjpf.htm
and of course..
https://pinside.com/pinball/forum/topic/vids-guide-to-ultimate-playfield-restoration

Need new drop targets or other Gottlieb parts?
http://www.pbresource.com/

If you ever want/need new boards, these are the best replacements ever made, and they add tons of features to System 1 games (skill shot, ball save, high scores, excellent diagnostics) Worth every cent.
http://www.flippp.fr/index.php?lg=en&pg=

Your backglass isn't that bad.

Don't forget to stop by and join the club!
https://pinside.com/pinball/forum/topic/home-for-the-gottlieb-sys1-sys-80b-guys-yep-i-guess-it-a-club

Last but not least - Congrats! Sinbad was my first game as well, and I deeply - deeeeeply- regretted trading it off. I recently got another one back, and am in the middle of a restore myself. Such an awesome game.