The Culture novels can be read in any order — they share a universe but have no continuous plot. The most common recommendation is: start with The Player of Games (the best entry point, short, immediately accessible), then Use of Weapons (the masterpiece), then Consider Phlebas (publication order start, slower). Avoid starting with Inversions or The State of the Art.
The Culture is a post-scarcity galactic civilisation of humanoids and artificial intelligences. AIs (called Minds) run the ships and orbitals; humans live lives of complete leisure and freedom. The novels typically explore what happens at the edges of this utopia — where the Culture's values conflict with less advanced civilisations.
Use of Weapons is considered by most readers to be the best Culture novel — structurally innovative (told in alternating forward/backward chapters), with one of the most devastating final reveals in science fiction. Read it after The Player of Games so you already understand the Culture context.
