How far to go each day depends on your personal physical shape, age, trail condtions, etc. Yosemite trails are generally very well maintaned and their mileages stated on the maps very conservative- in other words if the map says 5 miles, it will be a "short" 5 miles. The 1.5 mph estimate for newbies is good. There are some tremendous elevation gains if you start from Yosemite Valley and go up to the rim. Each 1,000 feet of gain could add an hour. If you start at Happy Isles, by regulation, the first legal campsite is Little Yosemite Valley (3,000 feet gain). It boils down to how many hours you want to hike per day. Creek crossings are high now so it may take you half an hour to cross, by the time you take off shoes, put on wading shoes, get across, dry feet, put hiking shoes back on. With this years snow, I would add trekking poles and wading shoes (unless you hike in sandles)to your gear list. Actually you may want to ask rangers when you get your permit to help you choose a route that has bridges across major creeks.