I am looking for early readers, especially the rebus style, for my son who is almost 4.

I am also looking for books on teaching reading from a parent's perspective.

I recommend Ruth Beechick's Home Start in Reading.

I used a Spell to Read and Write and would highly recommend it. It is phonics, spelling, and reading which might be more than you want but that's all I know. I really like Ruth Beechick's works so I'm sure the above book is good as well.

I have several free resources listed at the Links for Schooling page (link in my signature).  Just select the Phonics category.  You might also want to take a look at the Free or Low cost category for free samples from vendors. 

We started with "teach to read in 100 easy lessons" (at home) but went with a beka later (at their christian school).

I have many easy readers on my shelf....make a deal.

PhonicsWorks from K12, Inc. worked very well for both of our kids.  And they enjoyed it!  Our son actually cried when he found out that there was no more PhonicsWorks after 1st  grade.  (He's over it now that he's in 3rd grade.)  = )

~Jori