Here are some helpful literacy sites for you to use.
Here is also some useful information to help you understand how speech develops
It takes about seven years for children to learn to pronounce speech sounds the same way adults do. Different children develop speech at different rates. In general, most children should make few mistakes with the listed speech sounds at the ages shown in the table below.
Hope it helps!
Speech sounds by age
Age Sound By around 3 b, p, m, n, h, d, k, g, ng (sing), t, w, f, y By around 4-5 f, sh, zh (measure), ch, j, s, and cluster sounds tw, kw, gl, bl By around 6 l, r, v, ng, and cluster sounds pl, kl, kr, fl, tr, st, dr, br, fr, gr, sn, sk, sw, sp, str, spl By around 7-8 th, z, and cluster sounds sm, sl, thr, skw, spr, skr