Nice - jumping directly into the deep end with AG, I see!
First question: exactly WHAT equipment do you have on hand? Most specifically, what do you intend to mash in?
Traditional all grain methods are very similar to what you describe - but you mash the grains for 60 minutes, then extract the wort from the grains, rather than remove the grains from the wort, if you follow what I'm getting at.
Here's how I would approach it, which might help:
- I'd mash the grains @ 155, as you suggest, in my cooler mash tun.
- After 60 minutes, I'd drain all the liquid I could from that mash tun into my boil kettle.
- I aim to boil 7.5 or so gallons (I expect to boil off about 1.5 gallons). So I take a look at what volume I was able to extract from the mash, and subtract that from 7.5. This is my sparge volume.
- I heat that sparge volume up to about 180F, then add half of it to the mash tun, stir, wait 10 minutes or so, then drain into the boil kettle.
- I then add the second half of the sparge volume to the mash tun, stir, wait 10 minutes or so, then train into the boil kettle.
- I should now have about 7.5 gallons of wort in my kettle, and I bring that up to a boil
- Once I reach a boil, I give it a couple minutes, watching carefully for the hot break (it'll look like egg drop soup). Some folks scoop this out, I simply wait for it to happen and let it drop back into the kettle.
- Once the hot break is done, I set a timer for 60 minutes, and add my 60 minute hop addition
- When the timer reaches 30 minutes, I add the 30 minute hop addition
- When the timer reaches 0, I turn out the flame and add the 0 minute hop addition, whirlpool (stir it up fiarly rapidly) and let it stand, covered, for 10-15 minutes.
- After the 10-15 minutes, chill the wort, transfer to fermenter, and add the yeast
Give it whatever time it needs (yeast work on their own timetable, not yours!) for primary fermentation to complete. You'll know it's complete because your hydrometer (you have one, right?

) will give you a consistent gravity reading for 3 days in a row. Typically, this will happen in 10-14 days, but it never hurts to give the beer an extra week or so past that point.
Only after primary fermentation is done do you add the dry hops. Some folks will add that to the primary fermenter, some will transfer the beer to a secondary vessel and add the dry hops there - do whichever works best for you. Let the beer sit with the dry hops for at least a few days (to be honest, I've only dry-hopped once, so I'm no authority when it comes to dry-hopping).
After those few days with the dry hops, go ahead and package your beer - whether you keg it, or add priming sugar and bottle. If you're bottle conditioning, give it 3 weeks at room temperature, then a couple days in the fridge for the CO2 to dissolve into the beer, and you're good to go.