1) For those who are reading I Belive, there is a sequel called I Wish.
2) There is a fluffy set of random fluff that contains plot points to the I Wish and I Believe story arc. It is called I Love.
It shall contain these four stories:
And His World Was Round: takes place a few months after I Wish.
Chocolate Covered What?: takes place before And His World Was Round, but still after the events of I Wish.
How Much Wood (Can a Woodchuck Chuck?): Takes place during I Wish, but is an excerpt/standalone of it.
Ruba Dub-Dub, Su's In The Tub: Right after Susan returns to Caspian during I Wish.