First don't Worry about Rot simply Paint on a few coats of water Based Water Proofer to both sides of the wood . The same as used on decks and Fences . If you are in an Area where you would Worry about Termites simply buy a few blocks of candle wax melt in pot and brush on to bottom side of wood also Good for extra water proofing. Placing Cedar chips in the soil around the logs will help and Baking Soda Will keep the Weeds Away just Sprinkle some in and Water it in. Finally don't worry about Slipping On These Logs As they are Usually Cut By Chain Saw And Will Have A Rough and Rugged surface as is. Don't use Sand Between Coats it will prematurely peal off the water Proofing Finishes you use.
The Revolutionary Yardscape: Ideas for Repurposing Local Materials
Buy this book from amazon.com