"Spider-Man: Homecoming" is the homecoming of the neighbourhood friendly superhero to the fold of Marvel Studios. While it is not a complete return of the masked hero back to Marvel proper, he has found his place in the Marvel Cinematic Universe, and will get to play in its established playground. "Spider-Man: Homecoming" is a part of something much larger, and for that reason, it is bound to have more than a few easter eggs and references dropped inside it. While some of those mentioned here are just nice and quick winks to the source material, there are some that may have implications to the Spider-Man franchise or the wilder Marvel Cinematic Universe. Of course, we don't claim to have any inside knowledge of where all this is heading towards, so consider these just playful speculations (with possible mild spoilers) on what we noticed so far about "Spider-Man: Homecoming".
The first thing to get out of the way is to know where "Spider-Man: Homecoming" stands in the timeline of the MCU. Based on the plot revealed so far, it's safe to say that the events of "Spider-Man: Homecoming" takes places prior of the events of "Captain America: Civil War" and shortly after as Tony Stark drops him off to his normal life as a high school teenager. There are several scenes seen of Peter Parker talking about his involvement in the airport fight in "Civil War", and there might even be a chance to see how the fight rolled out from his perspective.
A huge component of the drama in "Spider-Man: Homecoming" would be Peter Parker earning the right to wear the Spidey-suit. Unlike the previous iteration of the suit from the previous versions, the suit in "Homecoming" seems to be provided by Tony Stark, with the appropriate upgrades and technology from Stark Industries, not only does the Stark version of the Spidey-suit allow Peter Parker to shoot a combination of webs from the web shooter (including the web bomb), it also has an attached drone, a parachute that can be deployed, wings and fits into anyone who wears it. There is also going to be a second suit that is likely being invented by Peter Parker and his best pal Ned that will be worn when Parker has his original suit taken away by Tony.
All of the first Avengers will be making a comic appearance (hint: Hulk gives it away). Aside from Tony Stark who has a significant role as Peter Parker's informal mentor and gatekeeper to joining the Avengers, other members of the original Avengers also make their own appearances too. While it shouldn't be difficult to spot Captain America still in his first "Avengers" suit, you will need to be more aware to spot Bruce Banner and Tony Stark's father, Howard, also in "Spider-Man: Homecoming".
So far the love interest in all iterations of Spider-Man has been a different character, and it's good to see that "Homecoming" would not be using the same character as Parker's love interest. For this outing, Parker (and Ned) would be gawking at Liz Allan. While not a notable couple in the Spider-Man canon, there was a short-term attraction between them in the comics. Fun fact, Liz ends up marrying Harry Osborn, who has not been spotted in the trailers so far, but Oscorp is never far away from a Spider-Man movie.
You might still remember how Spider-Man took down Ant-Man at the airport in "Captain America: Civil War", and that Star Wars inspiration is not accident. You will get to see how big a Star Wars fan Peter Parker really is from his room in "Homecoming". While Disney currently holds the rights to Marvel and Star Wars, we wouldn't put our hopes up to seeing any secrets for Episode VIII here.
A major drive of the story is that the villains are making use of technology gathered from the battle of New York from the first "Avengers" movie. While who is behind tinkering that technology to be used by criminals has not been revealed (yet), but this is the sort of mess that the Avengers has to clean up after saving the world from an alien invasion and killer artificial intelligence. To do that, Stark formed a new company called Damage Control to do the mop up, and there are several references to them putting away tech that can be used for ill. For a little extra trivia, the Damage Control crew did have its own comic series, and there were talks of giving them their own television series.