Its good!
It's very different from the movie in ways that I've really enjoyed. I don't want to spoil anything, but there's so many more characters in the book.
It's not long, you could probably finish it in a few hours, but I've been picking it up off and on at my work (service industry) when things are slow. I can't wait to read Solaris now :curry-space:
Other good sci-fi authors are Belyaev, Alexey N. Tolstoy, Zamyatin, and Bulgakov. They also have non sci-fi books.
For earlier authors, read Pushkin, Gogol, Lermontov and Goncharov.