I have not traveled since this brave new era

began last week, so forgive my ignorance.
Where do you get the clear plastic bags? Are they at the airport or do you bring your own? What size(s) are acceptable? What is their point anyway? Why not just put your stuff in one of the TSA bins & send it on through?
Also, I certainly hope they change the new regs on carry on bag sizes. They are simply to small for a laptop, charger, DVD's & NCH.......
What's happening with books? Are they still banned?