To understand most essential Astophysical processes, e.g. star formation,
acceleration and propagation of cosmic rays, one must understand
properties of MHD fluid. Those fluids are turbulent and their properties
are very different from those of laminar fluids that the theory usually
deals with. For instance, reconnection in turbulent fluids may be much
faster than Sweet-Parker rate even when no plasma effects are invoked.

I shall address a few basic issues that make a great deal of difference
for Astrophysics. First is the issue of turbulence decay time
scale. Numerical calculations usually show that turbulence can decay
within one eddy turnover time and this causes a big problem for molecular
cloud support. On the basis of numerical calculations which account
for the presence of sources of turbulence, I shall claim that the
rate of decay depends on imbalance of turbulence (i.e. the disparity of
the energy flux moving in opposite directions) and may be much longer
than it is usually assumed.

The second issue that I shall deal with compressible turbulence and will
show that the scaling of turbulent energy with the wavevector for Alfven,
slow and fast modes. In view of the found scaling I shall discuss cosmic
ray scattering in the presence of interstellar MHD turbulence. 
I shall show that some of the instabilities that are frequently referred 
in the literature are, in fact, suppressed in the presence of turbulence. 
Moreover, the efficiency of cosmic ray scattering is substantially reduced 
due to Alfvenic turbulence anisotropy. As the result, the isotropic fast 
modes are the dominant source of cosmic ray scattering.

Finally, I shall discuss the structure of magnetic field that is being
created by turbulence within various phases of partially
ionized interstellar medium (WNM, CNM, gas within translucent clouds)
and its implications for transport of heat, cosmic rays and star formation.