DNA-decorated colloids, open new possibilities for the assembly of networked materials. They consist of colloids decorated with specifically designed DNA sequences. Controlling the number of arms, length and DNA sequence, it will be possible to design a DNA colloid that will self-assemble in a very precise way. Theoretical and simulation studies are required to establish the general features of these materials. The study under which circumstances an arrested state is expected instead of an ordered structure, or a fluid-fluid phase separation is required.The relation between the gel line and the glass line, and the possibility to generate physical gels in a reversible way will be studied. Controlling the length of the strands, the bond energy will be tuned, so the physical gel can be formed in equilibrium as close as desired to the percolation line. The dynamic properties of these systems will be obtained with Molecular Dynamics simulations, and the phase diagram with Monte Carlo simulations in the grand-canonical ensemble, were an effective potential, recently developed, will be applied. We will study the mechanism of self-assembly, and the influence of the different parameters (T, length, sequence, number of arms), and the obtained structures will be described. DNA-materials will be the building blocks of new materials.