diff --git a/README.md b/README.md
index 07f1de5..0510dda 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,10 @@
+![pdf version](https://img.shields.io/bower/v/adminlte.svg)
 # Bitcoin_Ethereum_Blockchain_docs
 Collection of useful documents about Bitcoin, Ethereum and other blockchain technologies.
 ## To contribute
-To add a document to this collection please open a new pull request with a url of the proposed document.
+Contribution are always welcome and recommended! Here is how:
+
+Fork the repository (here is the guide).
+Clone to your machine git clone https://github.com/YOUR_USERNAME/Blockchain.git
+Make your changes
+Create a pull request