One place to start would be a book like "Switching Power Supply Design" published by McGraw-Hill. I got the 2nd edition in my bookshelf but there probably is a 3rd or 4th edition by now. That book goes through design steps for nearly everything for every common topology at the time of publication. Complete with equations, diagrams, wafevorms, design examples, etc.
The topology is the general operating principle and component arrangement. Common types used in AC-DC converters include flyback, half-bridge, full-bridge and resonnant. Some designs are "current-fed", others are "voltage-fed". In current-fed topologies, the transformer driver switches have fixed 50% duty-cycle and output regulation is done by modulating the current using a buck regulator in front of the transformer. In voltage-fed topologies, the transformer is wired to the HVDC source and the pulse width is modulated to adjust output power. Voltage-fed designs are simpler but have a tendency to self-destruct because slight imbalances in how the transformer goes through its hysteresis loop tend to make it creep slowly towards saturation and when it gets there, it behaves almost like a short-circuit which will usually destroys the switching transistors.
Lots of interesting stuff in there if you like power electronics.