Blog Modification

Hi, I am wanting to shorten up my posts on the main page. For example I would like the title, a picture, and a sentence or two then a read more link that allows the reader to be transferred to the actual post.

Also, I am wanting to modify something and am unsure how to. This is what I am wanting..
I have a Travel page on my main menu, when the cursor is over it shows city guides and when the cursor is over that it shows all of the cities, and then you click your desired city and every blog post in that category comes up in full and you have to keep scrolling down and down. Is there a way to make it to wear when you click on the page travel it lists a small picture and the title of each travel post.. and when you click on city guides it list a small picture and the title to each of my city guides?

thank you!