@Dale Hazlett: Ok lets try and help one by one:
1. Widgets: These will already have a style in the theme just load them up and go 
2. Custom header: It should say the size by the header however if you do not have an advert showing it may be smaller due to padding.
3. I’d suggest you look at the video tutorial for Daily that should get you on track.
4. Images take the settings you have under your blog image settings for thumbnail, medium and large.