The third form can't always be determined just by knowing the second form, while determining the fourth form requires you to know to the third form and then applying rules which determine which of the handful possible endings you attach to the third form.
Knowing the second form is however still important since most endings for other case endings in singular are attached to a stem based on the second form.
As far as I know, the following English-Estonian dictionaries do contain the grammatical information for nouns and adjectives (i.e. the "four forms") and verbs (i.e. the "three forms") that you're looking for:
1) Saagpakk, Paul F. (ed.) "Eesti-inglise sõnaraamat" Koolibri, 2000 (ISBN-13 4741231018827)
Saagpakk's dictionary is old and has not been updated since the first half of the 20th century and what now exists is a reprinting of the last edition from over 50 years ago. Therefore some modern vocabulary and lots of slang that we're familiar with in 2009 will not be present in this dictionary. However it is big and every word's grammatical information (i.e. inflections for nouns, adjectives and verbs) is linked to inflectional tables or patterns of "model" words in the front of the dictionary).
2) TEA "Eesti-inglise sõnaraamat", TEA, 2005 (ISBN-13 9789985714249)
This big dictionary has a little bit less grammatical information than Saagpakk's, but it's newer and so a lot of the vocabulary and translations are more familiar to us in 2009. This dictionary shows the second and third form (but not the almost unpredictable fourth form) beside every noun or adjective, as well as the forms of the "-ma" and "-da" infinitives and present tense of every verb.
The following monolingual dictionaries also provide the required grammatical information for all words and are worth having if you're serious about learning Estonian.
3) TEA "Eesti keele rahvasõnaraamat", TEA, 2008 (ISBN-13 9789985717509)
This is an excellent dictionary for your purposes of finding grammatical information because for every
word you are shown more than just the basic forms/stems. For example, for any noun or adjective, this dictionary shows not only the four basic forms but also forms in other cases (e.g. "long" and "short" illative, nominative plural). Verbs get similar treatment since beside every verb you will see the three basic forms plus other participles and conjugations. If you use this dictionary just as a guide to find out the inflections of words, you won't be disappointed. Don't worry too much if you don't understand the Estonian definitions of the words themselves since you can use any Estonian-English dictionary to get a translation.
4) Erelt, Tiiu (ed.) "Eesti Õigekeelsussõnaraamat ÕS 2006", Eesti Keele Sihtasutus, 2006 (ISBN-13 9789985791639)
[This dictionary is also available as a free online database
Like the dictionary above, this too is an excellent dictionary for your purposes of finding grammatical information. However it does not show the information as explicitly as in dictionary in 3). This dictionary instead shows the grammatical information of every word by making the appropriate reference to a "model" word's grammatical information/patterns in the front of the dictionary. This method is the same as used in Saagpakk's big Estonian-English dictionary which I mentioned earlier in this post. If you use this dictionary as a guide to find out the inflections of words, you won't be disappointed. Again don't worry too much if you don't understand the Estonian definitions of the words themselves since you can use any Estonian-English dictionary to get a translation.
If you need to buy any of these books, the obvious source in Estonia is the Apollo bookstore (http://www.apollo.ee
). In the UK you can try Bay's Foreign Language Books Ltd. (http://www.baylanguagebooks.co.uk/
) and in the USA, Baltic Shop (http://www.balticshop.com
) may be able to help by making a special order for you. In any case getting these books will become expensive if they come as imports or special orders as the shipping and custom costs can be high.
I hope that this helps,