  In a recent paper [hep-lat/0701012] we presented precise lattice QCD results
of our European Twisted Mass Collaboration (ETMC). They were obtained by
employing two mass-degenerate flavours of twisted mass fermions at maximal
twist. In the present paper we give details on our simulations and the
computation of physical observables. In particular, we discuss the problem of
tuning to maximal twist, the techniques we have used to compute correlators and
error estimates. In addition, we provide more information on the algorithm
used, the autocorrelation times and scale determination, the evaluation of
disconnected contributions and the description of our data by means of chiral
perturbation theory formulae.
