Your accuracy drops while moving. You can improve it by crouching or lying prone, which also helps you stay hidden in bushes or tall grass.
These video guides provide step-by-step mission walkthroughs and essential tactical tips for mastering stealth and precision: Sniper Ghost Warrior [PAL][NTSC-U][ISO]
Mastering the game requires balancing stealth with precision shooting. Key interface elements and mechanics include: Your accuracy drops while moving
Use the mini-map to track enemy positions and always move carefully toward cover when the visibility indicator begins to rise. Walkthrough & Mission Guides and full mission walkthroughs.
For a direct look at gameplay without distractions, you can view the Full Game Walkthrough on YouTube which covers all missions and stealth sections.
The IGN Guide provides sections for basics, training, and full mission walkthroughs.