Confused at how to use Blogger.

It's definitely been a long time since I have posted in Blogger. Looking through, my page needed refreshing and I've given it an autumnal feel, hence the background. HOWEVER, looking through my posts there is one problem - why are they in different fonts???!!

I'm very confused and frustrated. How on earth did that happen? Tis strange and now I get to edit all my blog entries so they can match...can anyone explain to me why this is and how I quickly change it?

I'm a lucky girl. A very special somebody designed and created me a little logo for my blog. However, I have no idea how I can use it as a header..for now until I discover how I'll post up his design :)

I love the little gift and heart...