Add usage instructions to README

Author: orangeloop

README.md

@@ -1,8 +1,78 @@
 # Unit Of Work and Sagas
 [![Build status](https://ci.appveyor.com/api/projects/status/000g0ngc7jkf58sx?svg=true)](https://ci.appveyor.com/project/orangeloop/sagas)
 
-## Summary
-
 ## Installation
 
-## Usage
+##### .Net Core CLI
+`dotnet add package OrangeLoop.Sagas`
+
+##### Package Manager Console
+
+`Install-Package OrangeLoop.Sagas`
+
+## Unit Of Work
+
+When using with a Dependency Injection framework, three interfaces
+need to be registered:  `IUnitOfWorkFactory`, `IUnitOfWorkConfig` and `IConnectionStringFactory`.
+
+Implementations for the first two are included. You will need to provide an implementation
+of the `IConnectionStringFactory`.  
+
+Two abstract classes are included to make reading from the `ConnectionStrings` section
+of an application's configuration easier:
+
+ * `AppSettingsConnectionStringFactory`
+   * For loading from _appsettings.json_
+ * `ConfigurationManagerConnectionStringFactory`
+   * For loading from _app.config_ or _web.config_
+
+##### Example:
+
+###### appsettings.json
+
+```json
+{
+    "ConnectionStrings": {
+      "MyDB": "[Connection String]"
+     }    
+}
+```
+
+###### MyDBConnectionStringFactory.cs
+
+```CSharp
+public class MyDBConnectionStringFactory : AppSettingsConnectionStringFactory
+{
+    protected override string ConnectionName => "MyDB";
+}
+```
+
+### Usage
+
+The quickest way to get started is with the `DatabaseTask` class.  This class provides two methods: `ExecuteAsync` and `ExecuteAsync<T>`.
+Each of these methods will ensure the database connection is open, and that your code
+is executed within a transaction.
+
+```CSharp
+// First, create a DatabaseUnitOfWorkFactory.
+// In this example, we're working with a SqlConnection
+var factory = new DatabaseUnitOfWorkFactory<SqlConnection>(
+   new MyDBConnectionStringFactory(),
+   new DefaultConfig() // Sets IsolationLevel to ReadUncommited 
+);
+
+// Next, create a DatabaseTask
+var task = new DatabaseTask(factory);
+
+// Finally, execute business logic code
+await task.ExecuteAsync((unitOfWork) => 
+{
+    // We can now access the unitOfWork.Transaction
+    // For example, if we're using Dapper
+    var connection = unitOfWork.Transaction.Connection;
+    var results = await connection.QueryAsync<dynamic>("SELECT * FROM SomeTable", null, unitOfWork.Transaction).ConfigureAwait();
+
+}).ConfigureAwait(false)
+```
+
+