I am new to Cubase 7.
Is it possible to enter notes when scoring, in realtime with a midi keyboard ? i can see how to input a single note, but I want to be able to play from my keyboard and it notate…
I presume you mean, while the Score Editor window is open/frontmost?
If so, (and the same is true when recording in any of the MIDI Editors), you will have to create an empty MIDI Part first, so that the Score Editor window can open, then, just make sure that the MIDI track is record-enabled, then record normally.
Obviously, the way the Score will look depends on the track/staff’s default Display Quantize settings.
I mostly use Finale as a notation tool (mainly for fonts). However, it doesn’t do a good job of recording in real time.
I record into Cubase and save as a MIDI file and then open it in Finale. Cubase is much quicker to edit in than Finale.
You can also use the XML Import/Export.
Waiting for Steinberg Notation program 
I do the same with Sibelius. There is, however, a lot of editing work involved in getting readable parts to musicians, since MIDI-to-score translations are rarely exact, especially if the material isn’t simple. Not to mention you still have to add slurs, staccato/marcato and other markings and dynamics (I use a graphic tablet for that and literally draw slurs, nothing is as quick.)
Also waiting for Steinberg’s new application. I sincerely hope it will break new ground, especially in that department.