Since my comments earlier I have transferred a few PDFs to my Kindle. I found that if you increase the font size to at least 16pt (20pt is better) they are quite readable.

I increased the font in my song book to 16pt and have transferred it to my Kindle and it is much better than the 12pt I had originally. I have left the table of contents at 14pt to keep it all on one page even though it is a little on the small side.

Although I have my song book on my Kindle, I have not taken it to a singaround yet. I find my Blackberry much more convenient. I might try setting up a tune book sometime as that could be useful. It all takes time, though.