I am looking for books which contain a proof of Kronecker's Jugendtraum i.e. the imaginary quadratic field version of Hilbert's twelfth problem.
Though it seems to be solved even the case for CM field, for my knowledge problem, I want you to introduce a proof it requires up to global class field theory to me.
1) D. Cox, "Primes of the form $x^2+ny^2$", Wiley, 2013: Chap.3 (pp. 181-225) contains a detailed study of the theory of complex multiplication, starting from elliptic functions, modular functions, etc. to establish the "main theorem" of complex multiplication : " Let $\mathscr O$ be an order of an imaginary quadratic field $K$, and $\mathscr I$ a proper fractional $\mathscr O$-ideal. Then the $j$-invariant $j(\mathscr I)$ is an algebraic integer and $K(j(\mathscr I))$ is the ring class field of the order $\mathscr O$. In particular, $K(j(\mathscr O_K))$ is the Hilbert class field of $K$." As a complement, the fields generated by some remarkable singular moduli (e.g. the cubic root of the $j$-function) are computed in §3.
2) Cassels-Fröhlich, "Algebraic number theory", Acad. Press, 1967 : Chap.13 (pp. 292-296) by Serre is a compact (yet complete) determination of the maximal abelian extension of an imaginary quadratic field $K$ using the $j$-invariant.