Killing, yanking text

C-w — Kill active region.

M-w — Copy to kill ring.

C-M-w — Append kill.

C-y — Yank last kill.

C-S-<backspace> — Kill the whole line.

C-h v kill-ring — View the kill ring (not very readable).

Marking

C-x C-x — get back to mark.

Transposing text

C-t — Transpose characters.

M-t — Transpose words.

C-M-t — Transpose s-expressions.

C-x C-t — Transpose lines.

M-x transpose-paragraphs — Transpose paragraphs.

M-x transpose-sentences — Transpose sentences.

Working with windows

C-x + — balance windows.

Working with buffers

C-x k — kill buffer

C-x C-v — revert buffer

M-x ibuffer - interactive buffer list (deserves to be bound to C-x C-b)

Rename file and buffer

dired-jump -> R (or dired-do-rename) -> q