if you only want to delete certain keyframes (say instead of all the translate, rotate, and scale keyframes you just wanted to delete rotateX and translateZ) you can do that on the dope sheet. (window, animation editors, dope sheet)

select the object you want to remove the keyframes for, then start clicking on the plus buttons of the attributes you're interested in removing. to move the red current time bar in the dope sheet just change your time in the time slider below.