Internet of Things at home only
I recently worked extensively on a Home Automation Project and here's what I would recommend based off of that:


Use Arduino for hardware interfacing.
Use Raspberry Pi for hosting your server.
Write your server using Node.js (or Python if you wish).
Use Express, Socket.io (or Python simple server). Google these.
Use Serial (USB) for communication between Arduino and Raspberry Pi 
Use RF/BLE if you want to go wireless.
Use Redis or MySQL for database.
Use a graph JS API for charting.
To build an android app, send http requests (or a Socket.io link), for communication.


This is a simple to implement, but you'll need to put some time. Good luck.
All of the above steps are abstracted from each other. This means that if you want to incorporate additional features, you can change any stage without affecting the whole.