Well I got a close up filter just to get a taste of it (11 dollars, can't go wrong! ) and if I really like it then I think I'm going to upgrade to extension tubes with contacts or just go all out and get a macro lens! Thanks so much for the comment, it was very helpful!
For macro stuff, I've always used a HOYA Close-Up filter... you can get them at different magnifications - I have the +4 one. I've always been happy with the results it produced.
For a remote, I've always used a Nikon ML L3 (wireless). It's infrared, but I'm not certian if it will work with your D5100. I have D90 which is older than your DSLR. If it will work with yours then I'd highly recommend it. It's just straightforward and easy to use. Comes with a little carrying pouch/holder too.
I found one not long ago that is from a brand called Neweer, and it had a few features I liked, so I went ahead and bought it It will be a while before I get to use it since it's going somewhere else, but I can't wait!
Extension tubes are certainly a good alternative for near-macro photography. Do consider if the set you buy has electronic contacts or not, as the lack of these will mean you have to focus and set the aperture manually, if at all possible.
Lens filters work just fine, they will probably take some quality from your images, though they're fun to play around with. If possible, borrow a set and decide if they're good enough or not.
Ahh yeah I was looking at some extension tubes and saw that they didn't have contacts and that could be a problem, so I just decided to go with a cheaper filter, I'm looking forward to trying it out Thanks for taking the time to comment!
Instead of a macro lens, you can buy. Macro filters, which generally come in a pack of four - +1, +2, +4, and +10. The ones I got we're just under $20 on eBay, and you have to look for the macro filters which will fit your lens, for example mine were 52mm.
They're a really good alternative to macro lenses and give quite good results too
I really recommend them, I bought another set even though I have a macro lens, the awesome thing about them that I've found is that they tend to keep more in focus than the macro lenses do the closer you get to something
Hope they work really well for you and I can't wait too see some of your work when you get them