This information, found at the site, might also provide one with additional understanding of photos, e-mailing them, etc.
License: Freeware
Information:
This free image viewer and converter supports an extensive list of formats:
Supported file types:
AIF, ANI/CUR, ASF, AU/SND, AVI, B3D,
BMP/DIB, CAM (Casio JPG), CLP, DDS, Dicom/ACR, DJVU, ECW, EMF/WMF, EPS, FlashPix (FPX), FSH, G3,
GIF, ICO/ICL/EXE/DLL, IFF/LBM, IMG (GEM), JPG2000,
JPG, JPM, KDC, LDF, LWF, MED, MID/RMI, MNG/JNG, MOV,
MP3, MPG, MrSID, NLM/NOL/NGG, OGG, PBM/PGM/PPM, PCX/DCX, PhotoCD, PNG, PSD, PSP, RAS/SUN, RAW, Real Audio (RA), RLE, SFF, SFW, SGI/RGB,
SWF (Flash/Shockwave), TGA,
TIF, TTF, TXT, WAD, WAV, WBMP, WBZ/WBC, XBM, XPM, CRW, NEF, ORF, RAF, MRW, DCR, DXF
Since I am a novice computer user, I boldfaced those I'm familiar with, and am surprised about the inclusion of audio...mp3, ogg, wav, etc. SWF, too. huh. I have a lot to learn.

edit: I had to include more.
Some features of IrfanView:
Multi language support, thumbnail option, preview option, slideshow, drag-and-drop support, fast directory view, batch conversion, e-mail option,
audio CD player, print option, change color depth, scan support, cut/crop, IPTC edit, effects (sharpen, blur, Adobe Photoshop filters), capturing, extract icons from EXE/DLL/ICLs, lossless JPG rotation, EXE/SCR creation, many hotkeys, many command line options, many plug-ins