Can someone give me a brief on the process of F1 to H1 conversion?

Also generally i will join MBA school this august/september. Now im currently in H1 and would transfer to F1. My wife is on H4, and she plans to apply for her H1 in april. when ideally should i apply for my change to F1 visa?

Will her "H1 processing" be affected or her "H4 to Student dependant visa conversion" be affected, if she has already started her H1 processing, and she changes from H4 to Student dependant before her H1 approval arrives.

Is it legal to change from H4 to student dependant visa when aplication for H1is already underway.

How best to handle such situation, can you please help.