I found two baby bird eggs in my vent just now. How do I raise the baby birds and make sure they live?

The two bird eggs are gray with a slightly brownish shade and brighter gray splotches on them. They're about the size of a finger-nail. I know that since I touched them the mother won't take them back so I wan't to raise them myself to make sure they grow up well. What kind of birds are they? What kind of 'nest' should I keep them in to keep them alive( I don't have an incubator or anything like that)? Are they even alive? How can I tell? And how long will it take whatever kind of bird it is to hatch?