S.C.
I thought the book "The Happiest Baby on the Block" was really great too. It talks about 5 things you can do to sooth babies: 1) swaddle, 2) wear in a sling or wrap, 3) use white noise, 4) hold them so they're on their side, 5) use a pacifier (or breast, finger, etc) to sooth with sucking. You can do all of these things at once to really help. The book gives details on how to do each thing. For us, the swaddling and wearing in a wrap helped the most. Now, at 7 months, my son stops fussing just when he sees me pull out the wrap!
But, for most babies, this constant fussing goes away after 3 months, so hang in there and know that it's pretty normal, if you have ruled out any health problems. My son even had some reflux issues, which I thought contributed to his crying, but it all cleared up after 3 months.