So I thought it might be easier to post the options here rather than re-writing them every time I get a similar inquiry.

OPTION 1:
I use Dreamweaver by Adobe to design websites.  Adobe also sells Contribute (about $200) which a client can install on his/her computer.   Note: if you decide to buy it, please use the link on this page so I can make a buck or two.

Pros:  Pretty easy to use, especially if you’re willing to read directions.    (Surprisingly true for most products.)   Also, Contribute doesn’t care whether a site is built with PHP or ASP or plain old html, so it works with any web host.
Cons:   Expensive and not as intuitive as one might hope.  In other words, read the directions/help files.  Another con is that it’s software that you install on your pc.  So if you need to make a change to the website and you’re at grandma’s house, you’re out of luck unless you brought your computer with you.

OPTION 2:
A “content management system” which is just what it says.   WordPress, Joomla! and Interspire’s Website Publisher are just 3 of the many content management systems out there. The price of these range from free to $695 and up.  And that’s just for the product.  You will then probably pay someone like me to set it up and get you started.
Pros:  Pretty easy to use once it’s set up.
Cons:  Most require PHP and MySQL, which your current web host may not offer.   Not inexpensive to set up.

OPTION 3:
Use a blog for the parts of your website that need to be updated frequently.  I like WordPress because it seems to be more versatile and have more features than Blogger.
Pros:  Free –  if you don’t mind a URL that contains “wordpress” in it, like http://tomarketconsult.wordpress.com.   Also, I find it fairly intuitive. And if you don’t want to be very fancy, it’s pretty easy to set up.  Blogger is also easy, but it’s not as versatile.
Cons:  If you want it to be more integrated with your website and not have “wordpress” or “blogspot” in the URL, then your web host must support that, and you’ll pay a developer/designer to install it and set it up (anywhere from $150 and up, depending on how much customization and instruction you want).

OPTION 4:
You can also buy a full-fledged web design program like Dreamweaver or Front Page (now called Expressions, I think) or other.
Pros:  Complete control over your entire website.
Cons:  Do you really want become a web designer?    Unless you plan to spend a good portion of time (6 hours a week or more) updating your website, it’s probably smarter to pay a pro to update your site.

OPTION 5:
Microsoft Publisher.  Tons of people seem to have this and it can be used to edit websites.   If you have the ftp access information, you can download, edit and then upload pages on your website.
…. Changed my mind on this one after trying to help a client upload something. It’s just not made to layout web pages well. Use it for your brochures as it’s intended.

OPTION 6
Buy a shopping cart like PDShop Advanced.Net but don’t use it as a shopping cart (unless you actually sell something, obviously).  That’s what I did with http://www.trulytexan.com.
Pros:  It can be cheaper to set up than a content management system (as low as $600 for a decent looking site) and it’s easy to manage and add new pages, upload images, etc. if you’re willing to reading instructions.
Cons: Very menu oriented and sometimes not as flexible as I’d like.

My recommendation?

If you have an existing website that you’re happy with, but there’s a page or two that you’d like to update yourself, get Contribute.

If you are starting a new website or are doing a complete redesign, go with WordPress, TypePad or Interspire’s Website Publisher.