Need Help. This car is driving me crazy

My car would not go into gear. the clutch was not working. so i dropped the trans and found that my clutch and pressure plate were totally wore down and stuck together. so i replaced them, the throw-out bearing, and the slave cylinder. i put it all back together and it still has the same problem. a buddy of mine said that my slave cylinder may need adjusting or that there maybe some air still in the lines. help please.