U.S Security checks

[419]

I'm travelling to Orlando in a few days, and I was looking for info about the time in wil take me to get through the U.S security procedures.
I wil be arriving about 5pm on Friday afternoon. I want to know, as If it takes more than a hour or so, I will have to pre-pay for my hotel room. (It will be held for me until 7pm, unless I pay up front)

Also, how long does it now take to check in for U.S bound flights, as there is now extra security and visa checks.

Thanks for any info

419