I should have said:
"Make sure Replace mode is off" (because it is disabled by default).
This pic shows replace mode being ON. (The orange button in the Transport bar):
If you haven't already checked it out I'd highly recommend going through the Logic 101 tutorial here which'll get you up to speed in no time!
There isn't a direct feature to enable you to hear the previous (or all takes) during recording in Logic. You could unpack the takes to their own audio tracks... but I don't see the benefit of this "sound on sound" feature... wouldn't it become rather busy while recording if you have to listen to the 10 previous takes simultaneously?
Of course, you want to over dub only a section while listening back to the previous recorded part then using Options > Audio > Punch on the fly is the way to go
Then turn on "Autopunch" mode (next to Replace button in the pic above - the one with two arrows ).
Then drag the Red stripe in the Bar Ruler area to encompass only the section you wish to overdub. You can then hit record and play along. When the playhead reaches the beginning of the red stripe Logic will begin recording. When it reaches the end of the red stripe, Logic will stop recording, but continue playback.
A Take folder will be created too (unless "Replace mode" is enabled).
Hope this helps
Let me know if you need any more help :)