How did the crusades effect england

Richard went gallently off to war, leaving his brother, an incompetent ruler, in his stead. John was so bad that the Magna Carter was signed on his watch. That was helpful because it took some of the monarch's power away. It didn't help everyone since it only gave rights to some of the nobility, but it was a start.

That was one effect of the crusades in England. Richard the Lionhearted likely would have had the same difficulties that John had to cope with. Richard was not a great politician (he put rebellions down with force), but he was a very gifted military technician. John faced the problem of having not much of an army to resist those wanting him to sign the Magna Carta. That should  get you started.