I'm giving the credit for this tab to cojak_jr, since he submitted the chords.
All I figured out was the picking pattern for the lead riff off of what he had.
If you don't know what a specific chord is, go to the chord version of this song.

 ~~Light Up My Room~~
~The Barenaked Ladies~
::3/4 time::
=Standard Tuning=
-Fingerpicked-

*Verse*
e|-------------------------------------3-----------|
B|-------3-----------3-----------3-----------3-----|
G|-----0-----0-----0-----0-----0-----0-----0-----0-|
D|-------------------------------------------------|
A|-------------------------3-----------------------|
E|-3-----------2-----------------------------------|
   G           G/F#        Cadd9

*Chorus*
e|-------------------------------------3-----------|
B|-------3-----------3-----------3-----------3-----|
G|-----0-----0-----2-----2-----0-----0-----0-----0-|
D|-------------------------------------------------|
A|-------------------------------------------------|
E|-0-----------0h2---------3-----------------------|
   Em7         D/F#        G

*End-Verse / End-Chorus (One Bar Fill)*
e|---------3-----------3---------------3-----------|
B|-----------------------------3-------------------|
G|-----0-----------0---------------0---------------|
D|-------------------------------------------------|
A|-1-----------0-----------------------------------|
E|-------------------------3-----------------------|
   Gmin/B      A7sus4      G

*End-Verse / End-Chorus (Alternate Version for 2nd Repeat)*
e|---------3-----------3---------------3-----------|
B|-----------------------------3-------------------|
G|-----0-----------0---------------0---------------|
D|-------------------------------------------------|
A|-1-----------3-----------------------------------|
E|-------------------------3-----------------------|
   Gmin/B      Cadd9       G