yondeimasu is better*
yomimas(normal present tense)
yondeimasu(habitual tense)
you always read manga everyday,so [yondeimas] is OK (^-^)
but usually we(japanese) dont read manga everyday.
so [mainichi yondeimas+manga] sounds not good, maybe you love manga right?then you can say [yondeimas](^-^)
we use.....ex; [mainichi newspaper wo yondeimas]or[mainichi book wo yondeimas]
your grammar,tense is good. you will khow japanese feelings*sense*soon