Where can I find a good blues harpe (harmonica)?

Look for a Honer Marine Band harmonica.

your local guitar shop should carry a variety of them. honer have great ones, or anything really. they are as little as 15$
i suggest getting a G in order to be able to play in all the keys, otherwise there is a system to play in the right key. 5 up and 3 down or something, i forget but the guy at the store should know.

Any music store really including online ones. Hohner is my favorite brand. A great one costs around 15-30 bucks depending on where you are and what country you're from. I would get a harmonica with a plastic comb which is easier on the lips than wood. I would also strongly suggest getting it in the key of C because most teaching material or online videos use harmonicas in C. But when playing blues on a C harmonica you'll most probably be playing in G which is second position and a beginners and even advanced style of playing blues harmonica.

My favorite harmonicas are the Hohner special 20's and the Hohner blues harps. They aren't too expensive and have great quality and life.

Go to youtube.com when you get the harp for free online lessons. Just type in harmonica lessons.

http://musiciansfriend.com

coast to coast music is one source

Kevin's Harps is another good source. Search for both on google.

If you go to a music store, DON'T expect them to know anything about harmonica. In my experience they don't know what they're talking about. Also, DO expect a music store to have really high prices. You can usually talk them down by quoting a better price online.

Start with a "C" and go to youtube for beginner videos

All the Hohner hand mades sound somewhat alike. The reeds are the same on the Marine Band, the Special 20, and the Golden Melody. If you are slick and can tune and repair a harmonica without problems then the Marine Band should be OK. It is put together with nails and wood screws. If you fiddle with them when they are new to get them in tune, you might void the guarantee. I live at altitude and have better luck with wood combs because they distribute heat and therefore condensation better. The Special 20 and Golden Melody are put together with self tapping metal screws and bolts + nuts. The Special 20 and the Golden Melody have plastic combs, which are durable, safe, and easy to deal with. Special 20s are probably the best harps on the market for blowing chords. Golden Melodies have protruding reed plates that are not great for tongue blockers. But they work very well for overdraws. Golden Melodies are in equal temperament, which is better for single notes rather than chords. Again, you can change that if you are slick.
If you are a beginner, the quick and stupid answer is to get a Special 20, or a Lee Oskar. The vast majority of professionals give the same advice. After you have developed a well defined playing style, other brands and models will come into the picture. Write me if you are an experienced player with a specific idea of what you want and I will tell you which one you will do best with.
If you want to research harmonicas go to Coast2Coastmusic.com and read the reviews and customer ratings. They are very customer oriented. The other rational place to purchase your harmonicas is harpdepot.com. Expect to spend about 10 cents an hour to play the harmonica, if you don't repair and tune them yourself.
Prepare yourself for a lot of answers contesting which is better, wood or plastic. Aside from the heat distribution qualities and the beauty of wood, there is no difference in sound. The shape inside the harmonica, etc, controls the sound. The Special 20 and the Marine Band do sound slightly different for these reasons.
The Blues Harp is a MS for Modular System Harmonica. They come with replacement reeds and plates together so an amateur can repair them. Hohner sells two kinds of Harmonica. 1. The three hand mades described above. 2. MS models including the wood combed Blues Harp. Quick and stupid answer is that all professionals agree that the hand mades have superior reeds compared to the MS models. Of course, a professional can probably tune and repair a harmonica without the benefit of replacement parts.
Like all Harmonicas made in the orient [Lee Oskar and Suzuki are made in Japan, Cheap Chinese are a no go], I can't overdraw the thin reeds without rolling my tongue into a tube. I can do flat tongue overdraws on western harps like Hohner [hand mades], Seydels, and Herings. Hohners and Seydels are made in Germany. Seydels have no condensation problems and can be gapped very tight to make bends and overblow/draws absolutely awesome. Their chords are right up there with the Special 20. Seydels are the highest quality harps in the world. 1847.com Herings are made in Brazil and sound great at a low price. But they are constructed and serviced by a third world work force. If you don鈥檛 mind getting an oddball bad harp, Herings are a go. I recommend the 1923 Model. It is absolutely beautiful to look at, and also plays wonderful chords.
Those are the six places in the world where harmonicas are produced.

I seem to be cutting and pasting the same answer a few times today. Hohner has a very broad line of harmonicas that can be broken down into three catagories. 1 Hand Mades 2 MS for Modular System, and 3 Chinese made. You are going to spend about 10 cents an hour to play the harmonica if you cannot tune and repair them yourself. You are not going to save money buying a cheap harp. But you will waste money purchasing a harp with a metal comb.

As far as buying a set? You need a set to do accompaniment work with other instruments, and studio work, etc. Get yourself a good harp in C to begin on the right foot. When you get better it would be perfectly appropriate for you to get a high key and a low key for the tunes you like to play high and low. In the diatonic harmonica world, [95% are Richter tuned] G is the low key and F# is the highest key. C is used to accompany simple piano tunes. D and E are used to accompany simple guitar tunes, depending on how bold you are. Some people believe that the E lead guitar should be allowed to drowned out the D harmonica as a mater of courtesy. The piano is a C instrument, and the guitar is and E instrument. Both can be played in any key an expert wants to play them in. Same thing for a big chromatic harmonica [the ones with a button]. The diatonics have to be purchased in sets of 12 to be played in any key and any mode. But that is something that only an expert has to be concerned with. Get a good C and have fun. The most common keys are: C G A D E F Bb B. Most models come in the 12 keys that contain the keys in the western scale鈥檚 octave regardless of which is the high and which is the low.