Estimated achievement difficulty: 5/10
Offline: 33 
Approximate amount of time to 1000: 25-30 hours
Minimum number of playthroughs needed: 1
Number of missable achievements: 1 - "Time to Kill"
Does difficulty affect achievements: No difficulty
Unobtainable/glitched achievements: None
Extra equipment needed: None
Credits: Full credit goes to DerangedAsylum for providing videos for some of the achievements, and to GTA-SanAndreas.com for their import/export image.
Welcome back to Los Santos, playa. It's time to get back to gang banging. With improved visuals and a beautiful 720p resolution, San Andreas returns on Xbox 360. And of course, what would any remaster be without the inclusion of achievements? There is a small pattering of 33 achievements, with no online and, thankfully, no 100% requirement. This makes the list relatively easy, but the game can still take quite a bit of time due to some miscellaneous achievements and the sheer scope of content in the game. Here you'll be given the run down on what you need to do, what you don't need to do, and some tricks to get the 100% completion as fast as possible. Side note: Cheats do disable achievements, like the GTAs before it.
There are 100 missions in total spread throughout Los Santos, San Fierro, and Las Venturas, as well as some spread through Flint and Bone County. It is recommended to start and complete the first five missions or so to unlock the entirety of Los Santos and Flint County to explore, as well as to get some simple achievements and challenges out of the way. Since none of the missions in Los Santos are very hard, simply go through the story without worrying about anything else, yet, except for some easy ones like "Represent", "Get a Pump", "Pay n' Spray", "Hustle Some", "Assert Yourself Next Time", "Horror of the Santa Maria", "Trickster", and "What Are The Odds" – these can be completed right out of the gate if wanted, but these can also wait as they can be obtained at any time. Whether or not these are out of the way, simply progress through the campaign like normal. Once you reach Angel Pine, it is highly recommended to complete the Paramedic missions to get the maximum health possible (also netting the Paramedic achievement) for help with the rest of the game. Once that's out of the way, it is simply completing the campaign and mopping up with the miscellaneous achievements once those are done. Completing the campaign will net you "Getting Started", "All Dressed Up in San Fierro", "What Happens in Las Venturas..." and "End of the Line".
NOTE: See "Time to Kill" BEFORE completing the final mission as this is the only missable achievement in the game.
Once the game's campaign is completed, the rest of the Miscellaneous achievements can be easily obtained. It is recommended to get the vehicle specific ones like "Savior" and "What the City Needs" out of the way first, as they make CJ more impervious to damage. These can be completed at any time, but are recommended to be completed earlier for their benefits. Then it's simply going after the rest of them, which won't be too time consuming if CJ is appropriately equipped.
San Andreas HD is a remaster of a once great game now on a great console – thankfully the Rockstar gods chose not to torture us with the dreaded 100% gamestat achievement, but have instead given us a relatively easy achievement list that will hopefully be fun to complete.
[XBA would like to thank Dante Kasai for this roadmap]