diff --git a/build/README.md b/build/README.md
index a873c7d103077d8dbc81dea056f79cccf5349d10..e5ad51a76e39d33664884cdd536d0415523c5e30 100644
--- a/build/README.md
+++ b/build/README.md
@@ -4,29 +4,39 @@ This directory collects all the output of make builds.
 
 ## Instructions
 
-The original code produces output in the current working directory (the path where the code is executed from). The build directory is intended to collect local builds and test run output in a safe place, without cluttering the code development folders, thus helping git to filter out unnecessary logs through .gitignore.
+The original code produces output in the current working directory (the path where the code is executed from). The build directory is intended to collect local builds and test run output in a safe place, without cluttering the code development folders, thus helping `git` to filter out unnecessary logs through `.gitignore`.
 
 ## Code work-flow
 
-This section describes the use of the pre-existing programs, once the binaries have been properly built by a succesful run of make in the src folder.
+This section describes the use of the pre-existing programs, once the binaries have been properly built by a succesful run of `make` in the `src` folder.
 
 ### cluster
 
-1. cd to the build/cluster folder
-2. run edfb (./edfb)
-3. run clu (./clu)
+1. cd to the `build/cluster` folder
+2. run `edfb`
+   
+   > ./edfb
+   
+3. run `clu`
+   
+   > ./clu
+   
+*NOTE:* both `edfb` and `clu` expect an input which is assumed to be in a folder named `../../test_data/cluster/` (i.e. two levels above the current execution path)
 
-NOTE: both edfb and sph expect an input which is assumed to be in a folder named "../../test_data/cluster/" (i.e. two levels above the current execution path)
-
-TODO: set up a code variable to locate the input data (data file paths should not be hard-coded)
+*TODO:* set up a code variable to locate the input data (data file paths should not be hard-coded)
 
 ### sphere
 
-1. cd to the build/sphere folder
-2. run edfb (./edfb)
-3. run sph (./sph)
+1. cd to the `build/sphere` folder
+2. run `edfb`
+
+   > ./edfb
+   
+3. run `sph`
 
-NOTE: both edfb and sph expect an input which is assumed to be in a folder named "../../test_data/sphere/" (i.e. two levels above the current execution path)
+   > ./sph
+   
+*NOTE:* both `edfb` and `sph` expect an input which is assumed to be in a folder named `../../test_data/sphere/` (i.e. two levels above the current execution path)
 
 TODO: set up a code variable to locate the input data (data file paths should not be hard-coded)
 
@@ -34,4 +44,4 @@ TODO: set up a code variable to locate the input data (data file paths should no
 
 The execution of trapping programs requires at least one of the previous programs to have produced a complete output set.
 
-TODO: investigate which conditions allow clu or sph to write TTMS output files.
\ No newline at end of file
+*TODO:* investigate which conditions allow `clu` or `sph` to write `TTMS` output files.
diff --git a/src/README.md b/src/README.md
new file mode 100644
index 0000000000000000000000000000000000000000..29f340e1f259c9566529d369e6e9dc3923058a8d
--- /dev/null
+++ b/src/README.md
@@ -0,0 +1,9 @@
+# Folder instructions
+
+This directory collects the source code of the original programs and the development folders.
+
+## Instructions
+
+The original code is contained in the folders named `cluster`, `sphere` and `trapping`. Each folder contains a `Makefile` to compile either the whole program set or the single programs. A global `Makefile`, which contains instructions to build all the original source code, is available directly in the `src` folder.
+
+In all cases, build commands executed through `make` will output the object files and the linked binaries in the proper folders under the build directory.
diff --git a/test_data/README.md b/test_data/README.md
index 77cffcf6ab6d8abcae441501636c6484faa65d1c..ecab52cc207ec73532a925ee49074b63b9dd728f 100644
--- a/test_data/README.md
+++ b/test_data/README.md
@@ -1 +1,3 @@
-This directory collects the input files for test the code.
+# Folder instructions
+
+This directory collects the input files to test the code.