Musica Sacra has recently announced an online (free) collection of Communion psalms. For each Sunday, the antiphon from the Graduale Romanum is given together with the psalm, as recommended in the General Instruction.
Look in the sidebar for the heading "Chant Resources". There are two editions of the Kyriale (Solesmes and Vatican), and the complete old rite Missale Romanum. The files are very clear and printable pdfs. I'll be using the site to print off copies of the Missa cum Iubilo which we are soon introducing in the parish.