I have been trying to study elliptic functions and theta function for quite some time and have already got the hang of the classical theory (Jacobi/Ramanujan) based on real analysis, and now would like to study the arithmetical part related to imaginary quadratic fields and their relation to elliptic functions. Having very limited knowledge of Group Theory and Galois Theory (and things covered under Modern/Abstract Algebra) I tried to find classical references and stumbled upon Weber's Algebra, but unfortunately it is in German. Does anyone know if an English translation exists and if so how can it be obtained?

If there is no English translation available can someone point out any good references for "Imaginary quadratic fields and their relation to elliptic functions" keeping in view my very limited knowledge of Abstract Algebra.