I haven't done Franconia ridge but have done Algonquin. I've actually hiked Algonquin twice to the summit. The first time I tried it I turned back at the tree line in windy, winter conditions. I think it's a good option for a beginner as long as you're reasonably fit. My first Adirondack hike was Wright Peak. Wright is located just off Algonquin, and the hikes are the same for 90% of the distance. Algonquin wouldn't really be any harder. While I'm more fit now, I didn't exercise regularly when I did Wright. The trail to Algonquin is pretty easy to follow. Above the tree line you should pay attention to where you went up so you can follow down the same way, but in good summer conditions it's a piece of cake to do. Algonquin is an amazing hike and probably the best in the Adirondack High Peaks that's accessible to a beginner. Cascade is the "traditional" beginner summit, but I agree with your friends' suggestion for Algonquin.