Website needs tweaking

I need to make a small edit on my website. this is a blog, so you will have to know how to edit the css file. or the php file where the edit needs to be done. check out [login to view URL] on the right side under the yahoo ad block is is a big space under it. I want this space taken out. Don't send me generic introductions. I want to know you can fix this. this is a wordpress blog. should only take about 10 mins to fix