Here are a couple of snippets from the NY Times report.
By choosing Mr. Pence as his partner, Mr. Trump has opted both to bow to political convention and also to gamble on a comparatively untested choice. Mr. Pence cuts a far more generic political profile than Mr. Trump; he is viewed by Republicans in Washington and Indiana as a sturdy and predictable politician.
At the same time, Mr. Pence has a record of hard-line views on cultural issues that Mr. Trump has tended to downplay in the presidential race. In Mr. Pence, Mr. Trump now has a running mate who has advocated for defunding Planned Parenthood and restricting abortion rights, and who signed a religious freedom law that critics said would lead to discrimination against gays and lesbians.
... Mr. Trump could not afford a long delay in making his decision public. The Indiana governorship is on the ballot in November, and state law required Mr. Pence to file paperwork by noon on Friday in order to withdraw from the race and be replaced on the ballot by another Republican.
The Times also says that there will be a joint interview on CBS' 60-minutes this Sunday.