Starting from the beginning, it sounds as if you have a Foundations table
(tblFoundation) and a Guidelines table (tblGuidelines).

tblFoundation
   FoundationID (PK)
   Address
   Phone
   Other contact information

tblGuidelines
   GuidelineID (PK)
   FoundationID (FK)
   FundingAmount (currency)
   CanFund (Yes/No)
   FundingRange (should probably be two currency fields for upper and lower
limits)
   Other guideline information

From one of my previous postings in this thread:

Create a relationship between the two tables.  Click Tools -->
Relationships.  In the Relationships window, add both tables.  Drag
FoundationID from one table on top of FoundationID in the other.  Click
"Enforce Referential Integrity".  There should be a 0 on one side of the
relationship line and an infinity sign on the other.  Save and close.

Create a form (frmFoundation) based on tblFoundation, and another form
(fsubGuidelines) based on tblGuidelines.  On the property sheet  for
fsubGuidelines, click the Data tab and choose Continuous as the default
view.  With frmFoundation open in design view, drag the icon for
fsubGuidlelines onto it.  Switch to Form view, and try adding some data.

There is no need to combine the tables into a query for purposes of the
form/subform, although if you want to sort or otherwise manipulate the data
you can use a query based on a table rather than the table itself as a
form's record source.

As you have described the situation I don't see a need for a third table.

Sounds to me as though you are trying to link these table on a one to one
basis, ie OSI has one record of info in the Foundatuon table and one record
of info in the Guidelines table.  If this is the case combine the data in the
guidelines table with the foundation table.  You should not split up data
just to split it up.
If there is more than one record of guidelines for each record of foundation,
then what Bruce says.