Cakewalk liners were not actualy suited for mastering tools. You should pick something like Steinberg's Wavelab for serious mastering job. But if you know how to obtain a good mix with Cakey, you can go CD quality without pro-mastering. Make sure you export your mix to 16bit 44.1kHz wave stereo file.
There's no exact rule in EQ. Use analyzer or (better yet) your ears to judge how you should apply them on your tracks. Go Mixing / Mastering forum for mixing informations...