Preview! Launch it, in the Help menu go to the Preview Help docs, Show Topics, Edit Images, to Annotate An Image. It's all there, super simple, very flexible, very handy, and free.
Everything else you're asking, just go to the user manual section about editing in the piano roll.
http://help.apple.com/logicpro/mac/10.2.1/#/lgcpa9111b0d
Best place to learn Logic Pro X is this book. It is self paced, hands on, what we use of the Apple Authorized trainings, and I've done a LOT of LPX online courses, nothing is as good as this.
http://www.peachpit.com/store/apple-pro-training-series-logic-pro-x-10.1-profess ional-9780134185736
Here is the advanced book.
http://www.peachpit.com/store/apple-pro-training-series-logic-pro-x-advanced-aud io-9780134135816
They have a Updates tab for each book, with errata downloads to keep the books up to date with the latest version of LPX.