How does one get SEO, CRM, CMS, Social media and web update experience?

[D.Sage]

The best job I can think of that intersects all 5 markets would be to find a sales or business development job / internship in a medium - large sized SEM / Digital agency.

Most mid-large agencies use CRM to track client relationships. And if you're selling SEM / Digital marketing, you're bound to have to learn about SEO, Content Management Systems, Social Media and Web updates.

On the flip side, if you want hands-on experience with SEO, CMS, Social Media and Web updates, you'd be better off joining a small digital agency where they wouldn't have groups of employees specialising on each of those, but instead would have a handful of people doing it all. And there you could liaise with sales persons to learn about CRM.