more detailed explaination on windows build

windows/README.md

@@ -1,5 +1,23 @@
 The solution has been created with Visual Studio Express 2010.
-Make sure to compile the Release version, unless you need to debug the code 
+
-(and in the latter case modify the path in xgboost.py from release to test).
+How to Build Windows Version
-Note that you have two projects in one solution and they need to be compiled to use the standalone executable from the command line 
+=====
-or the python module respectively.
+* Open the solution file with Visual Studio
+* Select x64 and Release in build
+* Rebuild all
+
+This should give you xgboost.exe for CLI version and xgboost_wrapper.dll for python
+
+Use Python Module
+=====
+* After you build the dll, you can simply add the path to [../wrapper](../wrapper) to sys.path and import xgboost
+```
+sys.path.append('path/to/xgboost/wrapper')
+import xgboost as xgb
+```
+* Alternatively, you can add that path to system enviroment variable ```PYTHONPATH```
+  - Doing so allows you to import xgboost directly like other python packages
+
+R Package
+====
+* see [R-package](../R-package) instead