We just did my son's baptism 2 weeks ago, and had 20 people over afterward. I did "Neat Sloppy Joes", Apple Snickers Salad and a Broccoli Salad and chips and dip, and then a cake (I was going to buy the cake, but made one instead - I would suggest buying one to simplify.) We had assorted cans of soda and ice, and coffee and water.
Here are links to the recipes I used for the food - they were all simple and I made them all the night before - on this website you cna customize # of servings and it will multiply the recipe for you.
http://allrecipes.com/Recipe/Neat-Sloppy-Joes/Detail.aspx
Broccoli Salad
6 C raw broccoli pieces
1/4 C Sunflower seed kernels
1/4 C raisins
1/4 C Bacon Bits
Dressing - mix together and pour over the rest & stir up.
1 C Mayonnaise
1/2 C Sugar
2 Tbsp. Apple Cider Vinegar
The sloppy joes (I used 5 pounds of meat), I browned the meat and onions and celery, and then drained and added the sauce mixture, poured it into two 1-gallon ziploc bags and put it in the fridge overnight....in the morning I poured them into the crockpot and turned it on low while we were at church, and they were ready to go when we got home!
The Broccoli salad I used pre-cut broccoli florets for the salad section at Sam's club - they came in the right size bag,, 6 cups, too and the "real bacon" bacon bits in a bag rather than cooking the bacon myself, also used dried cranberries 1/2 raisins to give it a little more tanginess.
Here is the Apple Salad http://www.cooks.com/rec/doc/0,1743,151175-253203,00.html (almost as good as a dessert) - Chop up 6 sweet/tart apples (I used the Honey Crisp variety - you could use half Red Delicious and half Granny Smith) with peels on for color. Chill and chop up 6 full size Snickers candy bars into smaller pieces or slices. Fold all together with 1, 8 oz. container of Cool Whip. Let sit at least 1 hour, or overnight in fridge before serving. Easily doubled, which is what I did, and had leftovers after 20 people.