For the more complex exercises, I've found writing a working program in C first to be beneficial. At first I used Emacs Lisp because its nice to write in Emacs, which I'm using along with the Assembly major mode. C has less of a cognitive shift during translation since its much closer to what you're working with.
In a stoic sort of way, I have a new appreciation for C and an even greater appreciation for lisp. This, however, has not interfered with my enjoyment of learning MIPS, which I'm deriding much of from this book.
What are MIPS processors used for these days?
Not a lot of general purpose use anymore since the golden age of the SGI/N64/PS2/PSP.
Really, the only growth left for MIPS is through China's government's technology independence initiative in developing the Loongson/Godson CPUs, for which they licensed MIPS. A Loongson powers the laptop that RMS uses.