I have just done exactly this. Got a 100w panel of Amazon for £99, it's rated at 5.4 amps max (I think). Got a 10 amp controller (PWM) about £10 with an LCD screen, it shows; temp, battery voltage, charge current and load current.
Connected it up and had 3 very charged batteries ever since, I am not using all sorts of power hungry gadgets (just a TV and lighting) but on most days even the cloudy, rainy ones (which is most of them up to now) I have been getting 1.3 amps.
The batteries get charged until they are at 15 volts, then it knocks off and they drop down to 14volts, then it starts charging again. After dark the voltage slowly drops with usage but by the time I get up in the morning the panel has got batts up around 13.5v.
Just wait to see how much it produces in summer (if we get one).