Tony McManus Celtic Fingerstyle Guitar (two volumes with cd/DVD) is good but not easy or for beginners.

Now here's a suggestion if you are a brave soul. You could post an example of your playing. Not so that people can rip it to bits but so that advice given is more geared to you. You might be hyper critical of your own playing and only hear the mistakes or barriers and others might be more objective. It's not a dare or wind up.

Somewhere on Muscat there is a thread about vocal range and to aid practical discussion I put a little mp3 of me singing from the bottom to top of my voice and back. The responses were much more relevant than a more theoretical general discussion as it was based on what I could actually do