Blogs are more than just junior websites. Although a blog could be a static stand-alone site, the genre is designed for frequent updating and a measure of interaction between the originator or originators and the readers. If you intend to enter into a conversation with your readers, you are really searching for a social networking environment. But sharing genealogical information is fundamentally different than sharing recipes or discussing personal family matters.
It is abundantly apparent that the vast majority of people sharing genealogical information online are interested in the structured, family tree environment best represented by the huge family tree website such as Ancestry.com's Public and Private Trees and MyHeritage.com's huge collection of contributed family trees. There are dozens, perhaps hundreds of other alternatives with the same fundamental relationship between the information and the users.
There are a number of considerations to take into account before settling on one type of online venue for sharing family information. One of the first concerns is whether or not there is really a cooperative and supportive family organization behind the effort. Is the idea to have an online presence originating with an individual who is seeking family connections or an already established family organization that is funded and been in existence for years.
Individual efforts can be monumental, but are highly dependent on the dedication of the individual. A short online search will show a lot of abandoned family history blogs with last postings dating back a year or more. Maintaining a regularly posted blog requires an adjustment in life style and a passion for the subject matter that transcends an on-again off-again interest in genealogy. Genealogy is one thing, maintaining a blog is another. The same could be said for a website. But in the case of a website, benign neglect can turn into collapse of the site.
Blogs exist in a structured environment. Usually associated with either Google or WordPress, blogs are not dependent on the payment of annual fees or the vagaries of server issues. Websites do not maintain themselves, they requires frequent updating and maintenance to stay online. For example, you can build a website on any one of hundreds of server companies, such as BlueHost.com or similar sites, but then you are dependent of the server's viability and the payment of the periodic fees. The smaller or less commercially viable the server, the more likely that maintaining a website will require substantial periodic maintenance.
I suggest that until you have a formal family organization and as long as the online effort is mainly individual, that you may wish to see if a blog will suffice. Once you find that your family has an ongoing interest in family matters and is willing to maintain a regular fee payment, you could consider expanding into a website. Unless you have someone in your family willing to dedicate a lot of time to programming a website, you may have to also pay for third-party services for changes and maintenance.
If your main interest is just to get your information out there on the Internet so that it is available to other interested and potentially interested family members, you may consider many of the options available for building large information bases such as I mentioned with Ancestry.com, MyTrees.com and MyHeritage.com. A middle ground is available with the wiki based family tree sites such as WeRelate.org and FamilySearch.org's new offering Family Tree. These are free sites but backed by large, permanent organizations.
Personally, I do not have a supportive family organization. I blog about genealogy but do not necessarily share family information through this venue. I have my personal genealogy family trees parked on FamilySearch.org, New.FamilySearch.org, WeRelate.org, MyHeritage.com, Ancestry.com and some other sites. Although I do get an inquiry from time to time, I do not see the support necessary to justify either the time or effort to create a formal website.