I know from experience that trying to keep kids rooms/toy rooms tidy and organized is usually a huge time consumer! I have a few tried and true tips to help with this problem that all families with little rug rats can benefit from.
This is a task that you need your kids input and help, they need to have a say in what toys or books they no longer want. Don't do this when they are asleep or not home!! That would be a recipe for a kid meltdown! Let them know that the toys aren't going into the garbage, they're going to kids that don't have toys and would love and play with them.
1. Make up a calendar with stickers for the kids, this gives them a sense of accomplishment. Kids love cool stickers!! Crank up their favourite music and set a timer. Each day for 20 minutes,( it can be any day, your pick ( this way they don't get grumpy and rebel!) Work on one shelf or one bin of stuff, have a donation box ready and when it's full take it to the car asap. Toys tend to migrate back,(remember Toy Story, those toys get around!)
2. Once all the toys, books have been sorted through, this could take many days, the organizing time begins.
3. Watch and ask your kids where they like to play with their stuff. Some kids might prefer a certain spot on the floor or a special corner. Store those items there, less steps for clean up.
4. I prefer toys in clear containers so that the kids can see what's in it instead of dumping it out to find something. This can get visually messy, so storing them in a closed cabinet will help it look tidy.
5. Group like items together and items that are used together should be nearby.
6. Have all items at their level so that they can get and return items by themselves. They won't need your help and they gain independence.