You can make yourself a drilling jig with scrap wood. all you're looking to do is
make sure that the table is perpendicular to the drill bit, and then you want to
hold the blank perpendicular, too. You can make yourself a 90 degree corner to hold
the blank in, and as long as that stands up straight (all 90 degree angles) then
your blank will be straight. There's lots of different styles people have made. You
can probably find posts about drilling jigs if you do a search.
Sorry.. I forgot to mention that this advice assumes you have a drill press.
If your blank is longer than the quill travel, you can drill, stop and move up the
table for the rest of the drilling. If your quill travel is 2", that means you can
only drill 2" AT A TIME. But you can raise the table and drill deeper.