The Magic Tower had a library full of books on general magical knowledge.
There were also simple, but more important explanations and instructions about Long-Distance Teleportation.
Before Long-Distance Teleportation was activated, it would leave a hidden magic mark in place, which could only be detected by the spellcaster themselves, and even if they were separated from it by a dimension or two, it would not be affected unless it was forcibly uprooted by Dimensional Anchor, an anti-spatial spell.
The first successful Long-Distance Teleportation would perform teleportation in place, as there was only one magic mark.
And for the spellcaster to teleport somewhere else, either someone had to be willing to share their magic mark, or the spellcaster themselves would have to personally make a trip to their destination and use Teleportation once there, leaving their own private mark behind.
