The waterlands are just north of the city of Amsterdam and are easily accessed with a bike (and perhaps also a map).
I believe waterlands bike maps can be got at most larger bike rental companies in Amsterdam but I know for certain Macbike in the train station (outside on the far right) have them for sale at a meager 1€!
For many, biking in Amsterdam seems impossible; but getting out of the hustle and into the north (noord) can be a good introduction. All you have to do is go behind the Amsterdam Central train station and find the blue and white ferry boats. The best 2 to take are labeled ‘Buikslotemeerplein’ and run all day and night.
PLEASE be aware we drive on the right hand side of the road, so for safety please do your best to stay right. Out in the waterlands you won’t encounter too many other moving objects but when you do they’ll be moving at speed (unless they are other travelers like yourself). Think of biking in Amsterdam like driving on a hi-way… You maybe out for a Sunday stroll but not everyone is, so be considerate of those around you.
Once on the far side of the ferry boats and into Noord-Amsterdam you can follow signs north to the waterlands, it should take you roughly 15-20minutes to get out there. Depending on the route you take once out there within 15 minutes you’ll start to see cows and before too long signs from local farmers for coffee, tea and, my favorite, borenijs (freshly made farmers ice cream).
Monnickendam and Marken are an easy ride for people of all conditions. There are so many different routs you can take and if you are perhaps a bit fitter and pack a lunch you could easily bike all day and go past towns where you can see old traditional villages along with many many windmills. Volendam is a bit out and yet still doable for those intetrested in seeing an old Dutch *picturesque* village.
Good luck and happy travels.