1. Make sure you get the right translation
Unless you're reading it in Greek (one can dream), you are going to read a translated copy. While this presents a whole host of problems, one of the ways to make it easiest on yourself is by getting the right translation.
I read the Lattimore translation, and would highly recommend it. It's considered truest to the original text—line by line—which matters to me: I'm reading the Iliad to read Homer's poem, not the translator's. I also found the Lattimore's translation somewhat more accessible than the Fagles' translation of the Odyssey which I read last year. I was able to get into the poem, and wanted to keep reading—a wonderful feeling with such an intimidating book.
Sometimes the translator can be hard to find on Amazon or Kindle. Make sure to double check—all translations are not created equal.
2. If you're on Kindle, set the indicator to minutes
I can't remember where I got the habit of setting my Kindle progress bar (the text at the bottom of the screen) to minutes, but it helped me slog through the denser parts of the Iliad. Knowing how much time is left in a given chapter will make it easier for you to plan out how much reading you need to do per day, but more importantly, it will change quickly.
The Iliad is an almost 600 page book, and getting a little dopamine hit each time the number goes down is motivating. It also made it feel less intimidating—instead of having the number be something like "18 hours left in book", it is always a surmountable amount of time (Mine never got above 45 mins for a chapter). It removes obstacles to sitting down and reading, because it's easier to commit to 22 minutes at a time than an unknown "chapter".
3. Don't be overambitious
While this is always good advice, it's especially true for the Iliad. The first day I thought "I only need to read eight books a day, and I'll be done in three days." Though I'm sure this is humanly possible, I doubt any of us have the ability (on my best day I got through four). Two—which worked out to about an hour—per day was the optimal amount for me. It did take longer than I would have hoped to get through the book, but I didn't get burned out and was able to stay consistent.
4. Set a daily requirement
I touched on this in the previous point, but when you're tackling a book like this, you need to set an achievable requirement. You will note I didn't use the word "goal" here—it has to be a requirement. I set mine to two books per day, and took the requirement part to heart. Before I did anything I might consider "fun," according to my rules, I had to read a book of the Iliad if I hadn't read two that day. Want to read a news article? Iliad first. Want to scroll through Instagram? Iliad first.
5. Take the time to get into it
There are many books in life you can read a couple lines at a time, when you have a free moment. The Iliad is not one of them. I found I had to sit down and read a book at a time, and each time I tried to jump in for a couple pages, it required more effort than reading large blocks at a time. Commit the time to read a good chunk at once, and it will be more efficient.
6. It's okay to use CliffNotes
It's okay if you miss little details, or don't understand everything all the time. Homer refers to people by multiple names, and uses other techniques that can make the plot hard to follow. The CliffNote summaries are good, and only a couple paragraphs long per chapter. In conjunction with the book, it will let you stay with the plot, making the overall experience more enjoyable.
7. It's a poem, not a book—read it like one
There's a reason it's called an epic poem, not a book. Lines can run on and jump around, which can be disorienting. Sometimes sentences are repetitive or are arranged a certain way for effect, and it's important to not read it as a purely narrative book. Bask in the language instead of letting it drive you insane.
8. It's okay to go quickly through parts
I'm going to confess: I hate skimming. I know, I know: you're not supposed to be perfectionist about reading books. But I am, and I had to come to terms with that in the Iliad. You can't say you've read a book if you haven't read every word the author wrote in it.
And while I maintain this stance, in the Iliad there are paragraphs upon paragraphs upon paragraphs naming participants in battle. I had to speed up my reading, and be okay not thinking about these passages in order to get through them. It's okay to not think deeply about passages, nor remember them, but at least you've read them—don't skip them outright.