Toys! They're not just for the holidays! They're also for sex!
Toys can be great additions to your sex life, be it enhancing your "menage a moi" time or be it enhancing couples time. The most common toys are dildos and vibrators.
Dildos are insertables designed to stimulate the vagina and/or g-spot. They come in realistic shapes or in just plain smooth shapes. Some come with attachments to stimulate the clitoris at the same time. Some also vibrate. Some rotate. There are as many different kinds of dildos as there are colors in the rainbow. If you're trying a dildo for the first time, get something in the mid-to-smaller range, say 5" or 8". They come upwards of 12" or more and that can get a little...large. Doable, but really freaking large.
Vibrators are typically shaped like small eggs or ovals. They are sometimes attached to a remote, sometimes they're cordless. But they provide just that - vibration. They're great for pretty much anything. You can insert them anywhere or you can use them on the outside. They're great.
So how do you know what's right for you?
My first suggestion is to get up the courage to go to a sex shop. Look up local adult toy stores on Yelp and on Google to get good reviews before going. Any decent toy shop will take toys out of the packaging for you so you can feel them in your hands to feel how firm they are, how much they vibrate, etc. This matters because some of them can be pretty expensive. They're worth the investment if they're well made and if it's a good brand, but you want to know what you're getting out of it.
Too nervous to go to a sex shop by yourself? Grab a friend or a lover and take him with! You can giggle about the silly novelty stuff (fuzzy sex dice? Really?), make mental notes, and then if you're still shy, you can come back another time to make the purchase.
Going with a lover can be a really nice foreplay or a great present for an occasion. Why get you flowers when he can get you a vibrator? Go together, find something nice, let him pay for it and say "Happy Valentine's Day" and then go home and rock out together. It's an amazing date night.
The only problem with brick-and-mortar sex shops is that, like bookstores, their supply is limited to what they can stock and sell. If you want something more specialty or something they just don't have, there is always, always, the internet.
Googling "dildo" or "vibrator" or "sex toys" will get you tons of hits, but two of the best vanilla shops are Babeland and Good Vibrations. They're incredibly sex positive (clearly), they have great selection, and they have lots of customer reviews, which is really helpful when you're shopping online for something. There's even Amazon. (Seriously, what CAN'T you get on Amazon?) For sub-dom toys and furniture, I recommend BDSM Gear. All of their products are very well-made and to the point.
Whenever X travels for work, we usually find a time to get online together via chat (after work hours) and we start sending each other links of new sex toys we want to try. It keeps us in the mood even though we're three time zones apart and it gives us ideas of what the other person is interested in trying.
So why get toys at all? I mean, what's wrong with what God gave you? Short answer: nothing is wrong with the tools you were given, but maybe you want some variety. I love the way X's penis feels, but my dildo feels different and sometimes I want that different sensation instead, just like sometimes you want Rocky Road ice cream instead of Phish Food ice cream. Some things will provide sensations you just can't get any other way - a good vibrator can be used for all kinds of amazing techniques. If your partner tries to use his hands or mouth to vibrate that much, he will get tired really quickly, while the only limit on the vibrator is the batteries. Toys can also be great for when you're on your period - just use a toy instead of a penis and clean it off in the sink afterwards. Easy peasy.
And don't forget, nothing is stopping you from using more than one stimulator in a session. You could start with a vibrator, then use a dildo, then have coitus, then do oral, all in one session. Just a thought. Have fun!