First of all, I cannot recommend going electronic as soon as you can enough. You won't regret it.
First of all. Avoid web based logbooks at all cost. Nothing against them, some of them have great features, but all it takes is for the server to have a bad day, or the company to close up shop, and you are left with nothing.
Next, if you are well versed in excel or want to create your own, great! I however am a little bit more lazy (its my inner line pilot) and I went with one of the commercial solutions, and couldn't be happier. I can do 8710s in all of 5 minutes, and since I use my phone, all I do is drop the out/in times into my phone and it figures it out.
Now as far as to when to stop or if you should stop logging on paper, I waited until I had my initial ATP out of they way, and then stopped copying the entries over. Printed my logbook for the first time a few weeks ago using a $10 pack of paper and a $30 binder off amazon, and the beauty is over something spiral bound is I can print and add to it at home. From what I have heard the printed out reports satisfy recruiters and interviewers just fine, and if you are worried about signatures, LogTen Pro will do signatures too.