I would recommend you read what you usually read. Look for something of your interest, but in spanish. Go to wikipedia in spanish, use google chrome, install the extension "instant translate" and configure translation at double click. You will able to navigate and read, and when a unknown word appears, you'll make a double click and get the translation in a little tab, without having to go to another page for doing to that. It's a pretty convenient extension.
Greetings