While surfing various astronomy sites I came across 'Observation Manager', a German-made observing notes software. I've downloaded it as it looks interesting.
It is a nice, easy-to-use clean interface and you can enter information easily. The lack of a 'Help' menu is irritating, but the program is so easy to use that it doesn't really matter -anyway it was free so I can't really complain about anything I suppose!
To enter an observation, select 'Create Observation' and then fill in the necessary details of location, scope, etc. To add notes, click on 'Deepsky Finding Details'.
Another slight irritation is that the utterly pointless and waste-of-time 'Caldwell Catalogue' is in there and is the default option, rather than the RNGC (the RNGC is in there of course, but the list follows alphabetical order so Caldwell pops up first).
If you neglect to enter an observer or any other piece of data then the program will not let you proceed further, so you have to - annoyingly - scrap the observation, enter the required data in 'Create New...' and start again.
It's not a bad little bit of freeware though, but I'll stick with - mostly - my Deepsky program I bought at TSP a couple of weeks (a couple of weeks??!!) ago.