Here are some free downloads that may be useful; just click on the links to download.
The Manuals and one BG map require a PDF viewer. If you haven't got one you can download Adobe reader for free from Adobe
Baldur's Gate ManualBaldur's Gate Tales Of The Sword Coast Manual
Baldur's Gate Enhanced Edition Manuals
Baldur's Gate MapsBaldur's Gate PDF Map
Baldur's Gate Reference Cards
Baldur's Gate Portraits (including Enhanced Edition)
Baldur's Gate Wallpaper
Here are some wallpapers for your computer, available in different resolutions. If it's not the exact resolution you want, try them all and see which looks best. Click on the links to download them.
1280 x 1024 1600 x 12001920 x 1080 1920 x 1200
1280 x 1024 1600 x 1200 1920 x 1080 1920 x 1200
1280 x 1024 1600 x 1200 1920 x 1080 1920 x 1200
1280 x 1024 1600 x 1200 1920 x 1080 1920 x 1200
1280 x 1024 1600 x 1200 1920 x 1080 1920 x 1200
Baldur's Gate Enhanced Wallpaper
1024 x 768 1280 x 720 1920 x 1080 1920x1200
2480 x 1536 2560 x 1080 2560 x 1440 2560 x 1600
Candlekeep Wallpaper
1024 x 768 1280 x 720 1920 x 1080 1920x1200
2480 x 1536 2560 x 1080 2560 x 1440 2560 x 1600
Friendly Arm Inn Wallpaper
1024 x 768 1280 x 720 1920 x 1080 1920x1200
2480 x 1536 2560 x 1440 2560 x 1600
Sarevok Wallpaper
1024 x 768 1280 x 720 1920 x 1080 1920x1200
2480 x 1536 2560 x 1440 2560 x 1600