What steps do I need to follow to use my PPL for income?
This depends on your jurisdiction a bit since the nuances vary from country to country but in general to get paid to fly (or get paid enough to break even) you need to have at least a commercial pilots license. This would allow you to get paid to fly. With a CPL you can do lots of things like: 


Tow banners 
Fly charters 
Fly cargo 
Fly sight seeing flights 
Tow gliders (can be done for compensation with a PPL and proper endorsements as well see Rons comment) 


What many pilots go on to do if they are only looking for weekend break even fun, is to get their Certified Flight Instructor ticket and teach others to fly. This is a nice way to make some money, fly some beat up planes, and pass along the hobby to others. 

The speed to any licenses is hard to predict. It varies based on your time, money and aircraft availability as well as how good of a study you are. You also need to accumulate the hours required for a CPL which can take time. With good weather and a consistently working and free plane you can get through it in months. If you are a weekend warrior and only have access to busy rental planes and live in an area with weather it can take a few years to get everything done.