T.,
You are a woman after my own heart. I love Holidays even when the kids are young.
For the driveway. You can make paper bag cut outs and put some cand inside the lunch bags and illuminate your drive way. As it gets closer to halloween you can often find the paper bags already cut out in stores.
For the kids. Buy small pumpkins and let them paint faces on them. These can dry while htey are out trick or treating.
Make crafts. Michaels usually has a lot of kits that you can make 10 crafts all the same sor all the kids. Or if you like to internet shop try www.orientaltrading.com They usually have great stuff. Another great resources is www.familyfun.com They have great ideas but you have to do the shopping. I subscribed to there magazine when my kids were littlier.
Do fun food too. Publix usually has cute cookbooks in the check out line that are only a few dollars and have ideas for thinkgs like punch with frozen hands made out of gloves floating in them.
Bobbing for apples is always a good activity.
If you have a pick up truck or a trailer when you go trick or treating hall them all around in this. You can even put ahy in it for a hay ride. Take a cooler costumes and walking make you hat and thirsty.
When you are done trick or treating you can come nack to your house for Ice Cream Sundays. You can allow the kids to pick a candy or two and put them on the ice cream sundays.
You can also have a fire and roast marshmallows, Use chocolate from trick or treating for your smores.
Good Luck and do not think any ides is too much. Kids love over the top.