An ovulation chart will help you track your most fertile days.  They are simple to create and use.  You just need to take your temperature before getting out of bed each morning and when the temp goes up (often by .1 of a degree), then you are ovulating.  Having sex around the time the temp hits its peak is the best time for conception (that's about 2nd-3rd day of ovulation).

Your husband can raise his sperm count by avoiding alcohol, smoking, taking drugs, keeping up with fitness and a healthy diet, reducing stress, moderate sexual activity and increasin his water intake (to clear out toxins in his body).

At his age, his sperm count should still be quite high, depending on his testosterone levels.  My partner is in his 50's and still has a very high sperm count (and a 100% success rate of achieving girls!! LOL.  Poor hubby!), so age isn't the only thing you need to look at.  The older the man though, the more likelihood of having girls, but your hubby is under 45, so still 50/50 as to what you would get (it is the sperm that determines the gender of a baby).