Most pictures (from your camera, etc) are in jpeg format, which means that they've
already been heavily compressed. Putting such pictures into a zip file adds little to the compression, so they'll still take up just as much space as if you sent them uncompressed.
There are loads of file transfer services available, where you can upload your big files to a secure server on the web and then send the intended recipient(s) a link so that they can download them. However one of the easiest ways to access such a service is to sign up for a free email account with GMX. (You don't need to actually use the account for your email if you don't want to). That gets you 2Gb of free storage space, which you use to upload any files that you want. (So, for example, you could use it to store back-ups of all your important data). However there's also a 'share' option, where you provide the email address of someone whom you want to share a file (or folder) with and they're automatically sent a link to download the file(s):
http://www.gmx.co.uk