If your system is statically determinate (which in many cases means only two bearings) then you really shouldn't need software to find the loads on the bearings - this mainly involves things such as gear and pulley loads and simple moment reaction calculations etc. But if your system is statically indeterminate, which means that the bearing deflections influence the loads themselves, then there may be no simple software that will help, because you may need to incorporate detailed non-linear stiffness characteristics of the bearings. Each bearing can have up to three stiffnesses - axial, radial and tilt. Many bearing analysis programs also assume a rigid shaft - which may or may not matter. There are sites such as rbts.com and xlrotor.com that have free downloadable evaluation versions of their rotor dynamics software, which may help you. I have obtained free versions of the SPICAS bearing software from FAG in the past, but this depends on how friendly you are with the FAG rep. SKF also have software which you can obtain free sometimes. If you develop a good relationship with the rep of your bearing supplier(s), they will often do an analysis for you for free. If you have the bucks, of course, you can purchase very powerful software such as ABODE or COBRA. A simple FEA program may be all you need if it's available.