I see that you're locared in Turkey, so this may not work, but I usually use Google Maps to map out my route and calculate the mileage. You can easily manipulate the route and start/end points once you enter two addresses. Just divide the total mileage by the time you were out and about and voila -- you have a tracking method. For instance, if I biked to the local University campus and back along Summit Ave, I'll enter in my own address as the start point, the University as the end point (don't even need an address), drag the route off of Grand (the automatic map output) and onto Summit and then double the mileage listed in Google Maps (to reflect the "there" and "back").
There are also a variety of websites out there that allow you to create and share custom walking/running/biking/blading routes and fill in the details at certain points throughout (i.e. "overly friendly dog at such and such a corner -- make sure to cross the street if you want to keep your pace"). Some sites even allow you to upload photos of landmarks, views, etc. If you're tired of your own beaten path, you can check out routes that other folks in your area have uploaded or if you are visiting another city, you can find out where the "scenic route" is.
Hopefully that helps! Happy Trails!!