There are MANY different FREE platforms that you can choose to start your blog. Below are a few of the most popular sites to check out and see what works best for your needs.
Weebly is a SUPER easy to use. In fact, it's the platform I use for this site. It has a bunch of themes to choose from, features a drag and drop system for easy page construction and by far, the BEST customer service and help system of all platforms. If you choose to upgrade your account to Weebly Pro, you open up several elite features, including forums, slideshows, PayPal and eCommerce options. It doesn't have the expansion abilities of functionality that Wordpress can offer, but if you are not tech saavy and looking for an easy start, I suggest weebly!
Wordpress is probably the number ONE recommended blogging platform to use by bloggers and developers. It offers an enormous amount of functionality with plug ins (software that can be installed into your site to offer a wide range of upgrades such as virus protection, SEO optimism, event calendars, social media tools...etc). There are a TON of FREE and purchasable themes, which make it easy to get started with a pre-made design.
For online tutorials on steps to getting started, upgrading your site, installing plug ins or any other basic OR complex features check out www.bloggingwithamy.com. Amy offers a great, EASY TO UNDERSTAND site on the in's and out's of Wordpress!
Blogger is the blogging platform from google. A lot like Wordpress, it offers a number of pre-made themes to help you start with an easy design template. It features a drag and drop system for easy construction of pages. Some cool features are: Easy Google Adsense setup for instant monetization, Google Anaylitics to track your visitor stats and a feature to create a blog in which multiple users may access and contribute.