We present several results on relations between the Kolmogorov complexity of infinite strings and measures of information content (dimensions) known from dimension theory, information theory or fractal geometry. Special emphasis is laid on bounds on the complexity of strings in self-similar sets in Cantor space. Here a set is called self-similar iff it is the maximum solution of an equation of the form F = WF where W is a set of finite strings of length > 0 and F is the subset of Cantor space defined by this equation. It turns out that the Hausdorff dimension of these sets can be expressed in terms of the entropy of the language W, and that the Kolmogorov Complexity (or constructive dimension) of infinite strings in F can be estimated via Hausdorff dimension or entropy of languages. For sets in Cantor space definable by finite automata (regular \omega-languages) even tighter bounds of Kolmogorov Complexity via Hausdorff dimension or entropy of languages are obtained. Here results generalizing P. Martin-L"of's on the bounds for Kolmogorov complexity and oscillation of the complexity in an infinite string are obtained.