Did J.K. Rowling borrow heavily from J.R.R. Tolkien?

I wouldn't call it stealing. It's all just Norse Mythology. Fantasy is fantasy. Dragons, wise wizards and objects of immortality predated Tolkien as well.

I've read both books and I must say started to write a book of the same genre; but I have enough of imagination not to steal or borrow ideas from other authors. I think highly of Tolkien and his works, and he has inspired many, but not many got rich on it, did they? Tolkien borrow from other myths, he knew all those myth's before writing LOTR and Rowling did nothing of that. My friends told me she is an original author, but I say if your interested in a new Tolkien they you should start reading P.Pullmans work.

To tell the truth many books follow Tolkiens story, I mean look at what catergory that you put those characters in. Villian, Hero, Sidekick, Mentor etc. Many books have these things, like how else does a fantasy story go.

I love the Harry Potter series and I've seen all of the Lord of the Rings movies, first when I was very young and then again in highschool. When I watched the movies the second time, I couldn't help sitting there and saying to myself "Oh my gosh Harry Potter IS Lord of the Rings!" And I apologize for any of these things that are incorrect because I've only seen the movies... It's simply my interpretation from my own knowledge.
I know that many of the elements in both of the books are common in fiction, ex. dark lords, underdog heroes, ect... And while some point out the differences in detail between the two, I think that the real similarities are in how each of those elements interact with other characters and the plot.
While Voldemort and Saruman are powerful and evil rulers of a particular domain, (an extremely common foe in fiction), there are more specific things that make them the same. Both are looking specifically for the main character, (or the thing tied to him, in Frodo's case), because if they are not eliminated, the life or spirit of the villain may cease to exist in one way or another. The hero is the only person at that point who can defeat them. Also, Saruman is relying on an object, (the One Ring), to return him to power as he is only a spirit without it. Voldemort is also only a spirit without his Horcruxes.
In addition, the beginnings of the main series are alike in that they both start with the main protagonist's birthday. This, as well, is common in almost all books. But you should take the time to realize that more exactly, this birthday is a huge turning point in the character's life because it introduces them to an entire world or concept they never knew existed. Frodo is brought into the legend of the rings by Gandalf on the night of his birthday and must immediately set out on a quest to a far away place. Harry is introduced to the world of wizardry by Hagrid on the night of his birthday and must immediately leave to prepare for his adventure at the magical Hogwarts school. After the characters learn of these things, Frodo is given the One Ring and Harry is given the invisibility cloak as well as his school "supplies," (Frodo obtains his directly afterwards, Harry a few months later).
Of course there are the more minor, more common similarities such as Merry and Pippin / Fred and George, Dobbie / Gollum, the locket/ the ring... And there's also the fact that many of these things at the root are taken from myth and legend; but I personally find that there is much too much the same about Rowling's interpretation of these myths and common elements and that of Tolkien. Yes, there are these similarities between all fiction novels/series, but if this wasn't significant I do not believe that it would be so much more heavily noticed, even despite popularity. If the question is whether or not Rowling borrowed from Tolkien, I have to say yes.

Very few of the things on those list are differences in dramatic structure. The fact that both Dobby and Smeagol are pitiful creatures who can sometimes be helpful is not a valid comparison. Yes, they may look a bit similar in appearance but the ultimate test of whether it was simply "ripped off" is whether they both serve the same function in the story. Gollum is a vile, greedy, corrupted creature who wants to gain power from the Ring. Dobby is trying to HELP Harry and has no intention of doing anything otherwise.

The only comparisons you made that serve similar functions in the story are the Sauron/Voldemort, Frodo/Harry, Gandalf/Dumbledore, Aragog/Shelon and the goblins.

The One Ring is not loads similar to the Philosopher's Stone. The Ring is a dark object that will corrupt the owner. The Sorceror's Stone can be corrupting if it falls into the wrong hands but for the most part, it is an innocent object that is perfectly harmless if used for the right reasons. Nicholas Flamel kept the Stone for hundreds of years. Nothing happened to him.

And frankly, JRR Tolkien was not the first person to write about dragons, trolls and goblins.

the only big similarities worth mentioning are these:

Gandalf and Dumbldor are very similar characters;
Gandalf is a powerful wizard that helps Frodo,
Dumbldor is less powerful than Gandalf (according to some) and helps Harry

Sauron and Voldemort:
sauron is an almost unknown villain that has tied his soul to an object (the Ring)
voldemort is also almost completely unknown (at least up to the 4th book) and has also tied his soul to objects (his 7 horuxes)

both have big man-eating spiders

Gollum and Dobby are both small very skinny characters but their rolls in the stories are completely different

The rest of the similarities are too small or are in many other books to be actual similarities

Both series are my favorites and i have practically memorized the movies

both Sauron and Voldemort are called the "dark lord" and "Him"

blimey!!! i think you are reading a little too much into things, there are thousands of books and movies relating to fantasy as J.K has told it! I dont think it is a valid arguement because by the sounds of it you have watched the movies, and not read the books! if you read the books things will become a lot clearer especially from th 6th onwards where you see the bigger picture and the PHILOSOPHERS stone is small not the main weapon of power restoration!!!

LOTR: LONGBOTTOM-PIPE-WEED
ROWLING:LONGBOTTOM- CHARACTER
DUMBLEDORE- IN LOTR, FLYING INSECT
DUMBLEDORE, WELL, EVERYONE KNOWS WHO THAT IS...
INVISIBILITY: CLOAK
INVISIBILITY: RING
ANNOYING RELATIVES- SACKVILLE-BAGGINSES
ANNYOING RELATIVES- DURSLEYS
OLD FOREST-FORBIDDEN FOREST
TUNNEL LEADING TO DANGER- CIRITH UNGOL, WHOMPING WILLOW
MIRROR OF GALADRIEL: CAN SHOW WANT ONE WANTS TO SEE, MIRROR OF ERSIED & PENSIEVE, DO THE SAME
Concept the Dark Lord
Cannot Comprehend,
Ultimately Used Against Him
ONE RINGS DESTRUCTION, LOVE
~SLIM SHADY