@Vera, it's a personal decision, but I suspect most or at least many guests are glad to have breakfast in the place they're staying rather than to need to find a nearby restaurant or cafe.
To keep things simple, I offer a continental breakfast. This means uncooked, and very easy for me to provide (e.g. orange juice, muesli/cereal, yoghurt, fruit, bread/buns, toppings, etc., plus tea and/or coffee, and milk/coffee milk). If guests wish to start their day exceptionally early, they can simply help themselves to breakfast items on the Guest shelf in the cupboard and in the fridge.
I've only had seven lots of guests so far ( the latest is a couple that arrived yesterday from Germany), but everyone has told me how much they enjoyed the breakfast (a couple of people even mentioned it in their reviews). To me, it's a positive element, and part and parcel of being a welcoming host.
I know that some hosts simply leave thinks like bread/butter/ jam and tea/coffee/milk at the guest's disposal, while others go the whole hog with a full cooked breakfast.
If you prefer not to offer breakfast, though, be sure to state that very clearly in your listing description, and perhaps let potential guests know whether there are nearby cafes or restaurants.
