Securing android devices: Antivirus & firewall for android?

I'm a new user of android tablet and am curious how to scan for and remove malware from it. Also would appreciate some recommendations of antivirus and firewall programs, preferably free or cheap but still effective for android.

 

You can use Avast! Mobile Security & Antivirus for Android.
http://www.majorgeeks.com/files/details/avast_mobile_security_antivirus_for_android.html

 

I run ESET, which is paid av and Malwarebytes which is from on googleplay.
Only install apps from googleplay and your chances of getting nasty things on the computer are greatly reduced.

I don't run a fire wall.