You can watch a video of IF performing "Forgotten Roads" on Youtube . That video been posted and pulled a couple of times, so if the link doesn't work, just try entering 'Forgotten Roads' in the search line of Youtube.
Wikipedia has a good entry for IF
American musician Jim Newson has written with great insight and accuracy on the band
(except, i.m.h.o, about 'Woman Can You See (What This Big Thing Is All About)' - I've always thought that sounded pretty jazzy!).
You can read his detailed review of the first album here:
Jazz-Rock & IF1
Newson also writes in the All Music Guide,
where you'll find unusually apposite, separate reviews of the band and most of its albums.
IF were/are very popular in continental Europe, and those who understand German can read a review of the band and some of their albums here:
Babyblaue Prog Reviews - IF
Miguel Terol has info on band members, especialy Geoff Whitehorn, to be found here:
If you ask nicely, you can download a copy of a concert given on Swedish Radio
If you have broadband and Windows Media Player is your default music player, the first four albums are available for streaming here. See the bottom of the page for the albums, and higher up that page for details of how to listen to the music streams.
If you know of any other relevant url's that have information on the band that is not already to be found on this site, please let me know.