Ummm . . . seems to me Em played with capo on 2nd fret would be an F#m.
Because there is only one half-step between E and F, so a whole step (2 frets) above E is F#.
Likewise there is only one half-step between B and C, so a whole step (2 frets) above B is C#.
Astro5mile, use the capo as needed to move songs into your vocal comfort zone. Your vocal range can be broadened with practice - your vocal chords and larynx will increase their strength and agility with use. Better singing boils down to better breathing - don't hunch over you guitar and learn to draw a full breath (not a gut-buster, but rather a full and relaxed intake). Be just as serious about your singing as you are about your playing . . . both take practice.
The capo simply raises the pitch of the notes - but does not change the character of the chords. Major chords are still major, minors are still minor, etc.
You can also use chordie's transposing button to change a song's chord set into a key that is familiar to you. For instance, if a song is in F and has F, Dm, Bb, and C chords you can transpose up 2-half steps to G and then the song would have G, Em, C, and D for the chords. Transposing to a new key merely changes the scale you are playing in - it does not change the character of the chords.
Hope this helps - didn't mean to go on for so long . . . James
"That darn Pythagorean Comma thing keeps messing me up!"
[url]http://en.wikipedia.org/wiki/Pythagorean_comma[/url]