diff --git a/README.md b/README.md
index d31bab4..a1b2f66 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,35 @@
 # maphot
-My wrapper for using TrIPPy to do photometry of the same object in many images of the same field. 
-Work in progress.
+My wrapper for using ``TrIPPy`` to do photometry of the same object in many
+images of the same field.
+
+#``best``
+The ``best`` module that runs Source Extracter for all images in a set, 
+identifies sources that are present in all images, lets the user inspect and
+filter those sources (using ``TrIPPy``'s ``psfStarChooser`` tool) and then
+returns a Source Extractor-like catalog. 
+Having this "best" catalog speeds up the process of doing the photometry, as only a small catalog with known good sources are being used. 
+
+``maphot``
+The ``maphot`` module is the main body, which loops over every image in a set,
+performing photometry using the ``TrIPPy`` package of both the TNO and of all
+stars in the input catalog.
+
+#``photcor``
+The ``photcory`` module reads the star magnitudes measured in each image, 
+identifies stars that were measured in all images, displays the magnitudes as a
+function of image number to the user and aids the user to reject non-constant 
+stars (stars that don't follow the median trend) and then uses the median trend
+of these good stars to remove that trend from all star and TNO photometry, 
+resulting in (on average) constant stars and well-calibrated TNO magnitudes.
+
+#``fixzero``
+I think fixzero is not relevant anymore and can probably be deleted. It
+originates from a time when I had hardcoded the zeropoint to be 26 rather than
+using the zeropoint in the image headers, which is of course stupid. 
+
+#Warnings:
+Work in progress. 
+Only ever used by one person, so I'm sure it's full of bugs. 
+This code has only been tested on images from Hyper Suprime-Cam on Subaru. 
+Currently assumes that images are aligned.
+Currently requires image zero-points to already be callibrated.