Momo72, when I got in classical music a few years ago I had a
similar problem. I usually relied on friends to recommend recordings,
but also composers, I might like given the ones I already liked. Apart
from that I just exposed myself to as many different composers and
musical foms (symphonies, piano concertos, violin sonatas, etc.) as
possible and dug further if I liked what I heard.
Nowadays, I
read Gramophone and sometimes follow their advice. You should also get
a copy of either the Penguin or the Gramophone guides, both 1,000+
pages compendia discussing the various available recordings of a given
piece of music. Once you have bought a number of CDs, a favorite
conductor, orchestra or solo artist might emerge - or, you may find
that you like lots of different ones.
It has been great fun for me to explore all of this, and I hope you'll enjoy it, too.
Hedgehog