If I am understanding correctly, your loan will fund this CDFI's mortgage loans to borrowers in LMI tracts.
As far as the kind of CRA credits you will get, there are no hard and fast rules that will tell you if you make X number of loans for X dollars, you will get X amount of CRA credit. Examiners look at several different factors to determine if your level of lending is adequate. You will want to have a good understanding of what your assessment area "looks" like (demographic info, including what census tracts are included in your AA, and also how your peers and other lenders are lending in these areas). You will also want to have an understanding of the needs in that community. The greater the need for LMI housing in these areas, the more weight you will receive for the CRA "credit" given in the exam.
For affordable housing loans, I always include a copy of the loan presentation, which should include a description of the project, as well as the number of LMI units involved. You will also want to provide census tract information. I always geocode the address on FFIEC's geocoder and print the map and census information for my file. Depending on the type of loan you're doing, your documentation will look different. For example, if you're making a loan that will qualify under the Revitalize/Stabilize definition, you would want to explain how this loan will impact the census tract (or surrounding tracts) where it is located. Again, I would include a description of the project and a map from the geocoder.