Only shop at App Stores you know.
Google has taken steps to tame the Wild West that was its Market. It now has a “Bouncer” that scans the Market for malware. The trouble is that Android users can download apps anywhere. Don’t be lured into doing this. If you aren’t using Android Market, make sure you are in a store you know and trust, such as Amazon. Most Android models come with the default setting that doesn’t allow you to download apps from “unknown sources.” If you’ve fallen for social-engineering attacks in the past, it’s best to leave that box checked. When you download an app, try to get into the practice of checking permissions. If a game wants to send out SMS messages, for instance, that should be a red flag.