Where a hyphen appears at the end of a line, join the two halves of the hyphenated word back together. If it is really a hyphenated word like well-meaning, join the two halves leaving the hyphen in between. But if it was just hyphenated because it wouldn't fit on the line, and is not a word that is usually hyphenated, then join the two halves and remove the hyphen.
Keep the joined word on the top line, and put a line break after it to preserve the line formatting—this makes it easier for volunteers in later rounds.
See the Dashes, Hyphens, and Minus Signs section of the Proofreading Guidelines for examples of each kind (nar-row turns into narrow, but low-lying keeps the hyphen). If the word is followed by punctuation, then carry that punctuation onto the top line, too.
Words like to-day and to-morrow that we don't commonly hyphenate nowadays were often hyphenated in the old books we are working on. Leave them hyphenated the way the author did. If you're not sure if the author hyphenated it or not, leave the hyphen, put an * after it, and join the word together, like this: to-*day. The asterisk (*) will bring it to the attention of the post-processor, who has access to all the pages, and can determine how the author typically wrote this word.
Proofread end-of-page hyphens or em-dashes by leaving the hyphen at the end of the last line, and mark it with a * after the hyphen. For example, proofread:
something Pat had already become accus-
something Pat had already become accus-*
On pages that start with part of a word from the previous page or an em-dash, place a * before the partial word or em-dash. To continue the above example, proofread:
tomed to from having to do his own family
*tomed to from having to do his own family
These markings indicate to the post-processor that the word must be rejoined when the pages are combined to produce the final e-book.