Structural growth mechanisms for metal doped nanoclusters are investigated in combined experimental and theoretical studies. In particular, silicon, copper and gold clusters incorporating a transition metal dopant atom are investigated: Si_nX (X=Cu, V), Cu_nSc⁺ and Au_nY⁺ with n < 20. The doped clusters are produced with a dual-target dual-laser vaporization source. Structural information about the doped nanoclusters is provided by infrared multi-photon dissociation spectroscopy. Their size and composition dependent stability is studied with photofragmentation and mass spectrometry. A detailed understanding of the role of the dopant atom in the structural growth and in the electronic structure of the clusters is obtained by comparison with quantum chemical computations using density functional theory.