First you don't need to rush out and buy Photo Express or some expensive program... I always recommend Picasa. It is Google's photo program and it is free to download and does just amazing things... Last summer they changed the icons which I thought was a mistake but it is still the best around for free..
Even though they do a lot of the same things, they often have different terminology for the same action... Most have a tools for adjusting the overall color in a photo.... Some refer to saturation, others refer to color temperature and Google calls theirs "warmify" (weird). I like the ones with a little bar you can adjust and see the change as you do it.. Both my printer program and Picasa have that feature... Sometimes converting a photo will be listed under "special effects"
For some reason the color in the photo affects the results of the sepia.. It's not all that obvious but if you are doing a series, it makes a big difference.
Most programs allow you to adjust the temperature as well... With sepia prints, the warmer the tones the older they look... Here you can see the effect of adjusting the temperature. It is what Goggle calls "warmify".