Orientation of the red stripe on an IDE cable has 2 parts:
1. Motherboard connection: use the MB manual or printing on the MB itself to identify Pin 1 of the MB IDE connector - the red striped side of the cable should be on the same side as PIN 1. Most MBs come with a keyed cable that prevents you from connecting it in any other configuration. - Take a look at the cable and then look at the IDE connector on the MB; the notch in the body of the MB IDE connector should be obvious.
2. IDE device connection - assuming that you did connect the IDE cable to the MB with red strip on the PIN 1 side (probably the only way that a modern MB will let you do it), then the connection to the IDE device (HDD, CD-ROM, CD-R/RW etc.) should have the red stripe side connected to PIN 1 of the device's connector. - 99.99% this Rule of Thumb works: make sure the red stripe side of the cable is closest to the power connector of the IDE device.
Good Luck