For egg whites, one should avoid introducing them to babies until 12 months because they are one of the major allergy triggering foods but for egg yolks it's okay to try at around 9 months. Preparation wise, the egg can be hard boiled and mashed into small and soft pieces so that baby can either pick up the pieces or be spoon-fed.
However, if allergies are common in your family, or your baby has signs of other allergies, eczema, or asthma, it will be safer to wait for baby to be older (after 2 years).
As for chicken, most babies can start eating it as soon after they start solid foods, but you will need to puree it so it becomes tender and soft enough for their baby gums (and maybe tiny teeth).
http://www.parents.com/advice/babies/feeding/when-can-my-baby-eat-eggs/
http://www.parents.com/advice/babies/feeding/when-can-my-baby-eat-meat
And this website has pretty good recipes according to a child's age group:
http://www.cookinglight.com/m/food/recipes-for-babies-toddlers
Above all, remember to check with your pediatrician first ☺