I always just ignore the frequency options in the receiver tab (all the stuff on the right side), and just go for the values up at the top. I've found if you hover your mouse over the left-most digit, you can key in the exact frequency you want. You can also use the left and right arrow keys to go back and forth between digits and up and down keys to move them up or down, or mouse scroll wheel.
To be honest though, easiest thing to do is just make some bookmarks, and not have to worry about directly inputting frequencies, or use the scroll wheel on your mouse if you want to explore a bit.