Toilets, Sinks, Showers, Tubs and Disposals - Bathroom in basement

I was wondering how hard it would be to add a bathoom (toilet and sink) to an older home. We already have a shower down there which we don't actually need. Would this be a huge, costly idea???

Unless the basement was "roughed in" for these fixtures, you have a major job. Cutting concrete, installing drains, vents and water supplies. There is a solution. You could install a Macerating toilet. These have a pump that grinds the waste and pumps it to the main drainline. They also have inlets for a sink and even a shower. Try searching the Web for these. Good luck with your project.

I am undertaking this effort - bathroom in the basement , no roughins were done...looking for some good resources to help me figure out the plan of attack

As mentioned - it's do-able... but quite a job. I've added a couple of full baths in old basements and it's not a job I take on lightly. You're looking at finding the existing drain lines - cutting concrete to expose those as well as run the new drain pipes... refilling after inspection (permits a must). All the tools are available for rent - not cheap and not easy... dusty/dirty/nasty work.... but - for an ambitious DIYer with basic plumbing/concrete skills.... do-able.... And you'll be really proud of the finished product....