diff --git a/README.md b/README.md
index b0bbadf..f3c8d69 100644
--- a/README.md
+++ b/README.md
@@ -5,16 +5,15 @@ This Python tool has been developed to automate the installation of libraries fr
 ## Basic Usage
 To install the library `<lib>` using compiler `<compiler>` and MPI `<mpi>` make sure to have a configuration file `<lib>.json` in the `config` directory and invoke the tool as follows:
 ```
-./libinstaller --compiler=<compiler> --mpi=<mpi> --<lib>
+./libinstaller --compiler <compiler> --mpi <mpi> --<lib>
 ```
 To install all libraries with build recipes in `config`:
 ```
-./libinstaller --compiler=<compiler> --mpi=<mpi> --<lib>
+./libinstaller --compiler <compiler> --mpi <mpi> --<lib>
 ```
-For further options and their default values, please have a look at `./libinstaller -h`:
+For further supported options and their default values, please have a look at `./libinstaller -h`:
 ```
-usage: libinstaller [-h] [--config CONFIG] [--prefix PREFIX] [--src SRC] [--work WORK] [--keep-work] [--compiler COMPILER] [--mpi MPI] [--threads THREADS]
-                    [--verbose] [--separate-lib64] [--disable-shared] [--all]
+usage: libinstaller [-h] [--config CONFIG] [--prefix PREFIX] [--src SRC] [--work WORK] [--keep-work] [--compiler COMPILER] [--mpi MPI] [--threads THREADS] [--verbose] [--separate-lib64] [--disable-shared] [--all]
 
 options:
   -h, --help           show this help message and exit
@@ -30,4 +29,54 @@ options:
   --separate-lib64     Do not create symbolic links of files from lib64 in lib
   --disable-shared     Disable building of shared libraries
   --all                Install all libraries with config file in config/
-```
\ No newline at end of file
+```
+Per library configuration available in `config`, the corresponding `--<lib>` and `--<lib>-version`options are added automatically, eg:
+```
+--hdf5                          Enable build of hdf5
+--hdf5-version HDF5_VERSION     Set hdf5 version [1.13.2]
+```
+The name of the installation directory is automatically generated and has the form
+```
+<prefix>/inst-<compiler>_<compiler_version>_<mpi>_<mpi_version>
+```
+
+## Library configuration files
+The `config` directory contains various json files describing how to obtain and build the corresponding library. It must have the following structure (all keys are mandantory):
+```
+{
+    "name" : "mylib",
+    "dependencies" : "lib_a,lib_b",
+    "default version" : "x.y.z",
+    "download" : "git clone --depth 1 --branch hdf5-$VERSION https://myurl.com/mylib.git mylib-$VERSION",
+    "configure" : "autoreconf -fi ; ./configure --config-option --prefix=$PREFIX $SHARED",
+    "build" : "make -j $BUILDTHREADS",
+    "install" : "make install",
+    "object files" : "123"
+}
+```
+### name, default version
+On startup, the installer tool will read the configuration files in `config` and add coreesponding options to the argument parser. In case `--<lib>-version` is not set, the default version from the json file is used.
+
+### dependencies
+Dependencies are used to determine the best installation order of selected librarie to satisfy all dependencies. Note that it is assumed that you supply needed dependencies via `LD_LIBRARY_PATH` in case they are not part of the current install.
+Also note that `$PREFIX/lib` is automatically added to `LD_LIBRARY_PATH`
+
+### download
+Download command. This is being executed in a subshell. Make sure that it works in the shell used to start libinstaller.
+The command may contain the variables `$VERSION` which will be replaced by the selected code version of the form `XXX.YYY.ZZZ` or `$VERSION_UNDERSCORE` which will be replaced by `XXX_YYY_ZZZ`. 
+The files will be downloaded to the `<src>`directory
+
+### configure
+Configure command. This is being executed in a subshell. Make sure that it works in the shell used to start libinstaller. 
+The variable `$PREFIX` will be replaced by the installation directory. The vairable `$SHARED` will be replaced by `--disable-shared` in case the respective option is set when invoking libinstaller.
+
+### build
+Build command. This is being executed in a subshell. Make sure that it works in the shell used to start libinstaller. 
+The variable `$BUILDTHREADS` will be replaced by the number of threads set when invoking libinstaller (`--threads`).
+
+### install
+Build command. This is being executed in a subshell. Make sure that it works in the shell used to start libinstaller. 
+The variable `$PREFIX` will be replaced by the installation directory.
+
+### object files
+The number of `*.o` files generated during compilation. It will be used to draw progress bars in case `--verbose` is not set.
\ No newline at end of file