diff --git a/.gitignore b/.gitignore
index 5445cfb2408ba35334ed92f3b73dc38611cb3fde..7b057a87905cbf623b4b1a215625feb828e27e32 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,8 @@
 # nb tmp files
-*-checkpoint.ipynb
+**/.ipynb_checkpoints/
+
+# pycharm
+**/.idea/
+
+# vs code
+**/.vscode/
\ No newline at end of file
diff --git a/Index.ipynb b/Index.ipynb
index 0dc7639b9eb773e6ad1d56e9274d048866d2b5fd..49bd51efa17a8bb0a1fec5f3544df6d656655d7b 100644
--- a/Index.ipynb
+++ b/Index.ipynb
@@ -6,10 +6,37 @@
    "source": [
     "# Modeling and Simulation of Complex Power Systems\n",
     "\n",
-    "This is the repository of simulation examples based on Jupyter Notebooks. Currently available are: \n",
+    "## Simulation Examples\n",
+    "\n",
+    "On this platform you find the simulation examples based on Jupyter Notebooks. They are presented in the course **Modeling and Simulation of Complex Power Systems** by **Prof. Monti** at the **RWTH Aachen University**. Reviewing and modifying the simulation examples shall support the students in understanding the lecture content.  \n",
+    "\n",
+    "The following notebooks are currently available: \n",
     "\n",
     "- [Lecture 2 - Modified Nodal Analysis](./lectures/02_NA_MNA/VS_CS_R4.ipynb)  \n",
-    "- [Lecture 3 - Resistive Companion](./lectures/03_ResistiveCompanion/VS_R2L3.ipynb)"
+    "- [Lecture 3 - Resistive Companion](./lectures/03_ResistiveCompanion/VS_R2L3.ipynb)\n",
+    "- [Lecture 4 - Nonlinear Resistive Companion](./lectures/04_NLResistiveCompanion/NL_RC.ipynb)\n",
+    "\n",
+    "## Helping Material\n",
+    "\n",
+    "### Notebooks\n",
+    "\n",
+    "Learn how to work with the notebooks by accessing the extensive information under **Help** in the navigation bar. \n",
+    "As a first starting point you might refer to **Help>Notebook Reference**, where you can find **Notebook Examples** in the user documentation. Important basics are covered in the following sections:\n",
+    "\n",
+    "- Notebook Basics\n",
+    "- Running Code\n",
+    "- Markdown Cells\n",
+    "\n",
+    "### Python\n",
+    "\n",
+    "If you need an introduction to the Python language, the **Beginners Guide** under **Help>Python Reference** links to lots of tutorials depending on your previous knowledge.\n",
+    "\n",
+    "### IPython\n",
+    "As a more advanced user, you can benefit from the fact that Jupyter Notebooks run an **IPython** kernel, which comes with additional features with respect to the standard **Python** kernel. To learn more about these features, you can follow under **Help>IPython Reference** the link **IPython documentation** and have a look into **Tutorial>Introducing IPython**.\n",
+    "\n",
+    "### Contact\n",
+    "Any questions can be adressed to\n",
+    "[acs-teaching-mscps@eonerc.rwth-aachen.de](mailto:acs-teaching-mscps@eonerc.rwth-aachen.de)"
    ]
   }
  ],
diff --git a/README.md b/README.md
index bf9dcb9c70a26dbe96a3bbb930420cf20ba12dcf..4fecc9de45da3ce8c85cc6d0509d466793de6c28 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,33 @@
 # Modeling and Simulation of Complex Power Systems
 
-This is the repository of simulation examples based on Jupyter Notebooks. Currently available are:  
-- [Lecture 2 - Modified Nodal Analysis](/lectures/02_NA_MNA/VS_CS_R4.ipynb)
-- [Lecture 3 - Resistive Companion](/lectures/03_ResistiveCompanion/VS_R2L3.ipynb)
\ No newline at end of file
+## Simulation Examples
+
+On this platform you find the simulation examples based on Jupyter Notebooks. They are presented in the course **Modeling and Simulation of Complex Power Systems** by **Prof. Monti** at the **RWTH Aachen University**. Reviewing and modifying the simulation examples shall support the students in understanding the lecture content.  
+
+The following notebooks are currently available: 
+
+- [Lecture 2 - Modified Nodal Analysis](./lectures/02_NA_MNA/VS_CS_R4.ipynb)  
+- [Lecture 3 - Resistive Companion](./lectures/03_ResistiveCompanion/VS_R2L3.ipynb)
+- [Lecture 4 - Nonlinear Resistive Companion](./lectures/04_NLResistiveCompanion/NL_RC.ipynb)
+
+## Helping Material
+
+### Notebooks
+
+Learn how to work with the notebooks by accessing the extensive information under **Help** in the navigation bar. 
+As a first starting point you might refer to **Help>Notebook Reference**, where you can find **Notebook Examples** in the user documentation. Important basics are covered in the following sections:
+
+- Notebook Basics
+- Running Code
+- Markdown Cells
+
+### Python
+
+If you need an introduction to the Python language, the **Beginners Guide** under **Help>Python Reference** links to lots of tutorials depending on your previous knowledge.
+
+### IPython
+As a more advanced user, you can benefit from the fact that Jupyter Notebooks run an **IPython** kernel, which comes with additional features with respect to the standard **Python** kernel. To learn more about these features, you can follow under **Help>IPython Reference** the link **IPython documentation** and have a look into **Tutorial>Introducing IPython**.
+
+### Contact
+Any questions can be adressed to
+[acs-teaching-mscps@eonerc.rwth-aachen.de](mailto:acs-teaching-mscps@eonerc.rwth-aachen.de)
\ No newline at end of file