Last year I took to cycling in a big way (for one reason or another). One of the hardest things though was to find food (that I didn't make myself) to take on the rides. For some of the longer rides (a 600km weekend for example) it just wasn't practical to take made food for this long.
Here's what I found and take for a longer ride.
Hydration
Hydralyte Sports - I switched to this from the standard sport drinks because I thought it worked better (it's probably mostly psychological I know) and the satchels for a 600ml bottle are pretty handy to carry around.
Food
Bonk Breakers - They have a pretty silly name but they are pretty tasty (for energy bars) and all their products are gluten and dairy free. My favourites are the Apple Pie and Peanut Butter and Jam ones. They are a bit more expensive but they are worth it for the taste (and to find something that is gluten free.
HoneyShotz - I don't like the gels, they are super goopy and sticky. I generally get them all over my hands and jersey before I get any to my mouth. One thing I do love is Honey (who doesn't) and HoneyShotz are perfect for taking on a ride... And added bonus, if you happen to split a tyre the honeyshotz case is perfect for sealing the hole and getting you home.