The vehicle, which landed on the Red Planet in August, has driven up to a pile of sandy material that mission scientists have dubbed "Rocknest", NASA said in a statement.
The rover's ability to put soil samples into analytical instruments is central to assessing whether its present location on Mars, Gale Crater, ever offered environmental conditions favourable for microbial life.
Mineral analysis can reveal past environmental conditions. Chemical analysis can check for ingredients necessary for life.
"We now have reached an important phase that will get the first solid samples into the analytical instruments in about two weeks," said Mission Manager Michael Watkins of NASA's Jet Propulsion Laboratory in Pasadena.
The rover's preparatory operations will involve testing its robotic scooping capabilities to collect and process soil samples.
It also will use a hammering drill to collect powdered samples from rocks. To begin preparations for a first scoop, the rover used one of its wheels to scuff the soil to expose fresh material.
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Curiosity will scoop and shake a third measure of soil and place it in an observation tray for inspection by cameras mounted on the rover's mast.
A portion of the third sample will be delivered to the mineral-identifying chemistry and mineralogy (CheMin) instrument inside the rover.
From a fourth scoopful, samples will be delivered to both CheMin and to the sample analysis at Mars (SAM) instrument, which identifies chemical ingredients.
"We're going to take a close look at the particle size distribution in the soil here to be sure it's what we want," said Daniel Limonadi, lead systems engineer for Curiosity's surface sampling and science system.
"We want to be sure the first sample we analyse is unambiguously Martian, so we take these steps to remove any residual material from Earth that might be on the walls of our sample handling system," said Joel Hurowitz, sampling system scientist on the Curiosity team.