Agree with Mr. 737: doing airwork or practising landings on a PC sim with the intent of getting better in "the real thing" is a waste of time (fun though it may be), and you may have to concentrate more on looking outside during VFR training than someone who has never developed the habit of scanning an instrument panel in front of him/her.
On the other hand, apart from spending delightful and immersive hours, some of them in airplanes at least I could never afford (financially and training-wise) in real life, if you take flightsimming seriously, it can improve your skills in several areas, especially if you join one of the online flying networks (IVAO or VATSIM; forget any discussion about which is better, choose the one with more ATC coverage in the areas and during the times you "fly"). My personal benefits were/are:
- improved nav skills, partly from practising, partly simply from getting a better feel for how the surroundings look from above and how maps translate into actual terrain (depending on the quality of your sim scenery, of course);
- being very much at ease with VOR navigation;
- better feel for time and distances when flying;
- improved R/T fluency and proficiency, including VFR and IFR phraseology and procedures when flying from/to controlled airports (and including R/T in French);
- a sketchy grasp of the sometimes fundamentally different modi operandi for different types of airplane;
- a somewhat better feel for weather and terrain considerations;
- several harmless but humbling and quite insightful experiences of hopelessly getting behind the course of things and how quickly this leads to errors and omissions.
I also know of several real-life pilots who use PC sims for practising IFR procedures, but that's probably only beneficial if you have received formal training and can discuss these exercises with an instructor.