Look in your local paper or online for upcoming events like school fairs - often they'll take on stalls. Be wary of expensive craft fairs as I've found selling cards that you have to then sell a lot to get your money back, smaller events that aren't exclusively craft are often cheaper. My favourite is a regular stall I do at Cancer Research fundraising events as it is very reasonable but then if I don't make my money back then at least it's gone to a good cause.
Also if you're on Facebook you could take some pictures and upload them with some description and price so friends and family can see what you've made. EBay is saturated with handamde cards and they don't seem to sell but check out Folksy.com instead if you like using the internet. All the best for it