Basic SQL Help

Argh...someone smarter than me (probably all) please help me with this
little SQL thing. Here's my deal:

3 files
FILEA contains relationships (columns FILEA.PARENT and FILEA.CHILD),
where there is a 1-N relationship between parents and children. PARENT
and CHILD are SKU numbers. 
FILEB contains SKU numbers and identifiers (FILEB.SKU and FILEB.ID).
Valid IDs are 1=Collection, 5=Set, 9=Item. Collections can contain sets
and items.
FILEC contains SKU numbers and descriptive information (FILEC.SKU and
FILEC.DESC).

What I want is to have a result set (proper term?) that has this data
like this:

Collection1
  Set1
  Set2
Collection2
  Set3
  Set4
  Set5
.
.
.
Item
Item
Item

Where Set1 and Set2 are children of Collection1, Set3-Set5 are children
of Collection2, etc. I would then like all the items to be after all the
collection/set information. Since each entity has descriptive
information, I need each result set row to have the SKU number and
descriptive information. I also need things ordered by a column in
FILE1. 

Whomever can send me an SQL statement that could make this work would be
a hero, and I would be happy to answer any communication or RPG
questions they have to the best of my ability. 

I know...I need to learn SQL better. 

TIA...

-- 
  
  michaelr_41@xxxxxxxxxxxxxx