The electron transport properties of individual InAs nanwires and InAs/InAlAs core-shell nanowires are investigated. A temperature dependence characteristic of phonon and ionized impurity scattering is observed in fault-free InAs nanowires. A clear correlation is found between the presence of stacking fault defects and reduced mobility in lower mobility InAs devices. It is observed that phase coherent transport and electron interference manifest as conductance oscillations in InAs/InAlAs core-shell nanowires. The presence of shell structures in InAs nanowires strongly reduces the random telegraph noise and smooths out the distortions of local potential inside the core nanowire. These effects would be beneficial for the stability and tenability of sensitive low-temperature quantum dot devices. Gate-defined quantum dots and RF-SET charge sensor are integrated in Individual InAs nanowires for qubit manipulation and readout.