Cost effective and Quality Backing Track Solutions

Hello, im part of a band and we desperately need to set up a backing track system as too many of our songs cant be done justice with the extra guitars/keyboards etc that we are physically unable to play live on stage( we are a three piece).

We have a tablet which im guessing will be required somewhere along the line but

if anyone could give me some tips on a starting point that would be excellent.

We really have no idea where to even start.

Thanks.