How to calculate Feynman diagrams in phi^4

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For quartic scalar field theory these are some of the lowest order diagrams (taken from the solutions to 9.2 srednicki). I'm wondering if someone can give me an intuition of how to actually calculate them.

What I'm thinking is that vertices are $$\int \frac{d^{4}x}{(2\pi)^{4}}$$ and for the first diagram their would be two contractions $$\Delta (0)$$ because the propagators return to the place they originated at. So would the first diagram just be $$\Delta (0) ^{2} \int \frac{d^{4}x}{(2\pi)^{4}}$$

Self-studying is incredibly difficult! Any help would be much appreciated! :)
 

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Try finding your answer in this website:
http://bolvan.ph.utexas.edu/~vadim/classes/2004f.homeworks/HWpage.html

If it doesn't appear there then try searching for solutions to Peskin and Schroeder, try reading the book.

There's also the book called diagrammatica by Veltman if I am not wrong that should have a good description on how to calculate it for quartic term.