DH was also put on 25mg of Clomid every other day, after a zero sample the day we were supposed to have an IUI. He had SA's prior to that which had sperm, which was odd. About a month after going on Clomid, his numbers raised to lower-end normal - about 15 million instead of the "normal" 20 million. More than enough to use for an IVF with ICSI. He produced another sample the day of the IVF ER, but we never got the numbers. We only know that it good to use for that cycle and that we didn't need the frozen sample.
The only side-effect DH noticed since getting on Clomid has been an increased sex drive. Where he used to be happy enough going once a week, now he'll want it many times a week - and that's just fine by me! :)
Side note - DH's urologist said the Clomid helps about 1 in 3 men raise their sperm counts and that an increased sex drive was one of the more common side effects.