Yes, it is a part of a trilogy, but it seemed to me that it was also supposed to be a stand alone story. In any case, I never went on to read the next in the series.
I've been harping about what I didn't like about the book, so here's what I did like about it. I felt it was a pretty fresh portrayal of the much dealt with future dystopian society. I liked the idea of them being color-blind, and how his discovery of color was such a revelation. It had me going back before he starts seeing color to see if the author ever used any references to colors, and I don't think I found any, which is pretty commendable if you ask me. I thought the characters were well developed and when the Giver was giving him the memories, I found that particularly interesting and original. For a "children's" book, I didn't find it childish at all. The prose was easy-to-read, yes, but it didn't seemed dumbed down, and I found the ease refreshing at the time.