I grabbed the level maps and drew the route for rescuing all prisoners. How it works:

Start with red, then look at orange, then yellow, etc. Like the colors of the rainbow. Hopefully these maps help new runners!

https://imgur.com/a/keJydaJ

If you want more advanced strats (or just smaller timesaves):

Level 3 - In the vent, you can quickly turn straight down at the first path.

Level 4 - After climbing to the very top, get to the very end at the right, fall, then go back.

Level 5 - A faster route is to save the first prisoner marked in the guide for last. Leave him last, but get everyone else in the order shown.

Level 8 - When you go upstairs to rescue the 2 prisoners, save the bottom one first, then the top. Saves a bit of time.