I agree with Arthur. The Russian lenses are soft and lens copies have wide variance in quality, chromatic aberration, ghosting, distortion and sharpness. Most of these lenses are sold from Russia, Ukraine and Belarus.Two popular Russian lenses are the Helios 44M 58mm f2 (swirly bokeh), and the MIR-1B 35mm. The Jupiter 9 is 85mm and has 15 aperture blades but lens copies have a lot of variance.
If you want to experiment with some vintage lenses you could probably get some sweet deals on Takumar M42.
The Auto Chinon 55mm f2, Rikenon 58 f2 and Nikkor non-AI 58mm 1.2 produce nice soap bubble bokeh.
As for mounting, you could always get and M39-FX adapter from Rainbow Imaging for less than $15.00
If you want to see the characteristics of different lens, just go on Flickr, search the lens you are interested in and view some of the pictures.
Hope this helped.