How do I login to iCloud and view my photos?

What verson of iPhoto are you using? To use iCloud you must be running iPhoto 9.2.2 or later. The following is from this Apple document: iCloud: My Photo Stream FAQ

What do I need to use My Photo Stream?

To use My Photo Stream you need an iCloud account, compatible devices, and up-to-date software:

• iPhone, iPad, or iPod touch with iOS 5.1 or later
• Mac with OS X Lion v10.7.5 or later and iPhoto 9.2.2 or Aperture 3.2.3 or later
• Apple TV (2nd generation) with Apple TV Software Update 5.0 or later
• PC with Windows 7 or later and the iCloud Control Panel 2.1 or later for Windows

OT

To enable Photo Stream on your Mac enable Photo Stream in the System/iCloud preference pane

and in iPhoto's Photo Stream preference pane.

Also, do I need to use iPhoto to add photos? I don't like iPhoto. What's that under 'Manage Storage' and then 'backups'... how can I send things to be backed up?

Yes, you need iPhoto to add photos to the Photo Stream from your Mac.

That storage is only for mobile devices as described in this Apple document: iCloud: iCloud storage and backup overview

Hi, no you don't have to use iPhoto. I don't like it either, but it is quite good in some ways, and if you do use it, that's how you view your photos in Photo Stream on your Mac.

To get away from iPhoto, you first need to use it get to the other options. If you open iPhoto, then go to the toolbar at the top of the screen, click on iPhoto next to the Apple symbol, go to Preferences. This will give you a number of options, such as being able to choose Image Capture, or an application of your choice, when you connect a camera to your Mac. It also gives you options for editing images etc.

That said, using iPhoto isn't as bad as you may initially think, and it has got some reasonably decent editing capability. The beauty of iPhoto is that it does allow all your devices to sync easily so that you can access your photos anywhere.

I hope this is helpful,

Fred