Get out the POH.
Use graphs to calculate stall speed in landing config at a reasonable (ie Typical) min landing weight and max landing weight. You'll probably find in something like a C172 that there's only 3 or 4 knots difference.
Take the lower figure and multiply by 1.3.
Be at this speed and no more at 50' in other than gusty winds. If there is a gusty wind, direction irrelevant except tailwind, add 1/2 the gust value up to a limit of about 7kts...ie wind 10 gusting 20 add 7kts...wind 7 gusting 15 add 3 or 4 kts.
At 50'/Vref gently close throttle and land with the stall warning chirping (remember stall warning happens a few knots above stall) on one or both main wheels. Hold nosewheel off and gently lower to ground. Just keep applying more of whatever control inputs you had at touchdown. Apply very gentle braking as dictated by remaining LDA.
What's the landing speed?
I have no idea...never look at the ASI in the last 50'.
Chuck.
PS. If the POH is 20 miles away at the Flying School ring them and ask that they fax you a photocopy of the stall speed graphs.