Always shred or chop newspaper before adding it to the compost heap. Mix the newspaper into the pile or alternate thin layers of newspaper with other ingredients. And make sure the pile is moist. Mulches and compost made with newsprint are completely safe to use around flowers and vegetables. Printers no longer use lead-based inks.
Shredded newspaper is an effective and inexpensive mulch.
Studies at the University of Vermont indicate that a 6-inch layer of shredded newsprint, left intact, can help suppress weeds for two full growing seasons. It's also as good at retaining moisture in the soil as other organic mulches. Raspberries, sweet corn and tomatoes produce larger harvests when they are mulched with shredded newspaper instead of an equal amount of straw. The studies suggest that there may be benefits of using newspaper over some other traditional mulches. Shred the newspaper, then dampen it before spreading it as mulch.