i personally try not to sleep at all on shabbos afternoon because it isn't worth it to have to stay up at night.
try taking a long walk during the afternoon, learn pirkei avos, read kosher magazines, books, etc.
for bedtime there are some very good 'lesson a day' books out there. one thing i enjoy a lot is the meam loez in english on tanach, the way it's written is almost like a story.
www.eichlers.com/torah-anthology-vol-20-yehoshua-joshua.html
anyway, kutgw and make sure not to get lulled into a false sense of security