You can visit heath at every time of season, because in every season it has it's own charm, during spring everything blooms, in autumn everything are in yellow colors and there are also berries. But if you'll be there early in the morning, probably will see some bird.
I've been there many times, so I suggest, when you start to walk by airing trail, to walk straight ahead, when road divides, to continue your walk only straight, you'll come back from that another road. Continuing your walk, there will be bird watching tower. From here you can have good view to the heath.
Walk is pretty long, so I suggest you to take good shoes or boots and to take with you water. It longs approx. 2,5 hours, if you're not hurrying.
There is no entrance fee and you can visit heath when you want. There is also possibility to reserve a guide.
If you think, that going here you need to take with you rubber boots, than I'd say no. Here in heath, is made fantastic airing trail where you can move around very easy and comfortably. There are many small lakes, which look like small puddles, but looking in the lakes you won't see anything, they aren't clear and transparent. Remember it's not allowed to swim here.
On both sides of trail you can see many mosses and berries, which in real you can see only in autumn, if only somebody before you haven't eat them. The heath is very moisty, therefore trees, which grow here, are small and thin. While you walk here, you may get feeling that here lives anyone and everything here is extinct. But it's not so, here live many birds and sometimes you can see snakes also. When I was there I heard cuckoo :)
If you won't hurry, you'll see plant, which eats insects, interesting :) I saw it.
Although in spring you may see here blue anemones and many other small flowers blooming.
If you're going to Kemeri, than it's worth to visit Kemeri city centre where is located sulphur spring and, of course, also taste it :). The spring, which flows out of small lizard is healthy and it can be tried, of course, if you'd pass the first test and walk to the spring. Smell is very strong here - real test for your nose. If you ask me, did I drink it - no, I just washed my hands :)
Not far from Kemeri are located sulphur lakes, but I haven't been there yet.
Near the spring you can see the hotel of Kemeri, which was built before war, in classicism style. Then it was very popular place, but nowadays it has been renovated.
First of all, you have to know that it is more convenient to come here by car or to ride a bike so that you would be able to see all of the Kemeri Nactional Park's (Ķemeru nacionālais parks) objects, because they are not all at one place and there are too long distances to go by feet.
If you are coming by train to the station "Ķemeri" in line Rīga-Ķemeri-Tukums you are able to take with you your bike on the train for some extra fee or you can rent one at the station "Ķemeri" and another place where you can rent a bike for your trip is at "Valguma pasaule" Holiday Centre, but in that case you have to go by train to the station "Smārde" and then walk more than 6 km till "Valguma pasaule", which is less convenient. You can reach Kemeri (Ķemeri) by bus and microbus as well.
Luggage and bags:
Take only what is really necessary.
Clothing/Shoes/Weather Gear: Take some clothes that mosquitoes can't get through and sandals or closed shoes would be suitable. And a rain coat and/or wind stoper jacket.
Toiletries and Medical Supplies: You should definitely take some spray against mosquitoes, because most of the park's territory is wetland and last summer (2010) it was very warm and from June-July/August there were millions of mosquitoes! Yeah, sure, some say that having like 100 bites of mosquitoes makes your immunity system work better, but- you choose! :) And from experience, yeah, after a week or two being in the nature and getting used to those bites, you just don't feel it so much, but if it's your first day at the park and into the wild- better be prepared! And for your information, there are two small shops that I know in Kemeri and some people told me that there were no anti mosquitoes sprays, so better take them from your home or get them in other towns.
Miscellaneous: Take a binocular with you as well and you'll be amazed what you've missed when you looked without it in the nature!