A good testosterone dosage for a steroid cycle is 400-500mg/week.
Here is a good video for you to watch on how to properly run a first steroid cycle:
https://www.youtube.com/watch?v=qqBLCSaKsW4
Long estered testosterones like testosterone enanthate or testosterone cypionate are the best option for a first steroid cycle because they only need to be injected twice per week.
Remember to include an AI (aromasin) to your cycle to keep estrogen in the low-normal range. This is very important to prevent estrogen related side effects like gyno. Start the AI on day 1 of your cycle and run it throughout your entire cycle.
Here's what I recommend:
Weeks 1 - 10
testosterone e or cyp 500mg/week (inject 250mg twice per week)
aromasin 12.5mg every other day
After your cycle run the perfect PCT protocol:
http://www.evolutionary.org/the-perfect-post-cycle-therapy-pct/